
The sabotage attacks on Saudi oil tankers in the Gulf of Yemen were carried out using limpet mines, experts believe.

The mysterious 'sabotage' has sent tensions spiralling in the Middle East as the U.S. blamed Iran and its allies for the attack - which divers said appeared to be the work of magnetic explosives.

Amid a furious exchange of words, a key adviser to Iranian president Rouhani warned of a looming conflict and mocked Trump ally John Bolton, saying: 'That's what happens when you listen to the mustache.'

Tensions had heightened further today after two pumping stations on a major Saudi oil pipeline were attacked by explosive-laden drones, halting the flow of crude along it.

Saudi Energy Minister Khalid al-Falih said attacks on the pipeline from the oil-rich Eastern Province to the Red Sea took place early this morning, and called it 'an act of terrorism' that targeted global oil supplies.

But both sides today tried to calm the situation. Iranian supreme leader Ayatollah Ali Khamenei said there 'won't be any war' while U.S. Secretary of State, Mike Pompeo, said the U.S. 'fundamentally does not seek any war'.

Trump also dismissed claims that the U.S. was plotting to send 120,000 troops to the Middle East, calling the reports 'fake news'.

Donald Trump is mulling over the idea of sending 120,000 troops to the Middle East while Iran's President Hassan Rouhani has warned his country is 'too great to be intimidated by anyone'. Tensions were increased further today in the region as Iran-aligned Houthi rebels claimed to have carried out drone attacks on Saudi oil installations

Norwegian oil tanker Andrea Victory, another of the four damaged boats, pictured with a large dent in its stern on Monday morning

The A. Michel tanker under the flag of the United Arab Emirates, pictured on Monday, was one of the four tankers damaged in alleged 'sabotage attacks' in the Gulf the previous day

President Hassan Rouhani (pictured last night) has warned Iran is 'too great to be intimidated by anyone' after the Pentagon claimed Tehran used explosives to sabotage four commercial ships anchored off the UAE coast

Saudi Energy Minister Khalid al-Falih said attacks on the pipeline (file picture) from the oil-rich Eastern Province to the Red Sea took place early this morning and called it 'an act of terrorism' that targeted global oil supplies

Spain has temporarily pulled one of its frigates, the Mendez Nunez (centre front) that's part of a U.S.-led combat fleet from near the Persian Gulf because of mounting U.S.-Iran tensions

Kremlin slams America's 'maximum pressure' campaign against Iran as Pompeo prepares to meet Putin in Russia The Kremlin has slammed Washington's 'maximum pressure' campaign against Iran, speaking hours before President Vladimir Putin receives US Secretary of State Mike Pompeo in the highest-level talks in nearly a year. Pompeo will visit Putin in the balmy Black Sea resort of Sochi to see if Russia and Washington can make headway on a raft of disagreements from arms control to the raging Venezuela and Iran crises. U.S. Secretary of State Mike Pompeo (left) and Russian Foreign Minister Sergei Lavrov (right) shake hands prior to their talks in the Black Sea resort city of Sochi today The visit comes amid mounting tensions in the Gulf, with Iran and the United States engaged in a new war of words over Tehran's nuclear deal with world powers. Pompeo is the highest-ranking US official to see Putin since July when US President Donald Trump met him in Helsinki and stunned the US political establishment by appearing to accept the Russian leader's statement at face value that he did not meddle in the US election. 'On some issues we may agree, on others we may disagree, but when it's in our national interests, it is our responsibility to find a way forward,' Pompeo tweeted on Tuesday. Peskov slammed what he called Washington's 'maximum pressure' campaign on Iran, saying it would only drive Tehran into a corner. Pompeo cancelled a stop in Moscow scheduled for Monday to meet in Brussels with European foreign ministers, who have been uncomfortable with the hawkish direction of the United States on Iran. Advertisement

Today divers on the UAE coast told Splash 24/7 that the damage to the tankers looked like the work of limpet mines.

The Pentagon claimed Tehran or its allies was behind the use of explosives to blow holes in the four commercial ships.

The US has deployed B-52 bombers and an assault ship to bolster an aircraft carrier in the region.

Meanwhile, the White House is reportedly planning to deploy 120,000 troops to the Middle East if Iran attacks American forces in an alarming echo of the Iraq War - but Donald Trump has denied the claims.

Asked about the damage, Trump warned that Tehran would 'suffer greatly' if it enraged Washington, predicting a 'bad problem for Iran if something happens'.

The war of words continued when President Hassan Rouhani responded by warning Iran is 'too great to be intimidated by anyone'. The Iranian leader told Sunni clerics that 'God willing we will pass this difficult period with glory and our heads held high, and defeat the enemy'.

This morning, Yemen's Iran-aligned Houthi rebels said that they had targeted several vital Saudi targets with drones in response to the kingdom's 'crimes' in Yemen.

'The targeting of Saudi vital installations is a response to the aggressors continuing to commit genocide crimes and impose a siege on the Yemeni people,' tweeted Mohammed Abdusalam, spokesman for the Iran-aligned Huthis fighting the Riyadh-backed government.

Oil infrastructure sites belonging to the country's state-run oil company Aramco were targeted with a fire breaking out at a station along the pipeline.

Iran-backed Houthi rebels, who are battling a Saudi-led military coalition in Yemen, had earlier claimed to have targeted several vital Saudi targets with drones and later said it was meant to send a message to the kingdom to 'stop your aggression' on their country.

The Houthis have repeatedly launched drone and missile attacks on Saudi Arabia and claimed to have launched drone attacks on the UAE.

On Twitter, an official was quoted as saying, 'This large military operation is in response to the continued aggression and blockade of our people and we are prepared to carry out more unique and harsh strikes.'

Saudi Arabia and the UAE are leading the Western-backed Sunni Muslim alliance that intervened in Yemen in 2015 against the Houthis to try to restore the internationally recognised government ousted from power in the capital Sanaa in late 2014.

What is a limpet mine? A limpet mine is an explosive which uses magnets to attach itself to its target. It gets its name from the sea snail which uses its feet to cling tightly to rocks and other surfaces. It was developed by British scientists during World War II, to be attached to the hull of an enemy ship and detonated from a safe distance. British operatives used the most powerful magnet in the world at the time to attach around 4.5lbs (two kilograms) of explosive to an enemy ship, capable of punching a large hole in the hull. Divers would carry the limpet mines underwater and attach them to ships, causing devastating damage when they exploded. Seven Japanese ships were sunk or disabled by Allied commandos alone, using limpet mines in Singapore Harbour, 1943. Divers now believe the same technology was used to target oil tankers in the Gulf of Yemen. Advertisement

The conflict is widely seen in the region as a proxy war between Saudi Arabia and Iran. The Houthis deny being puppets of Iran and say their revolution is against corruption.

The drone attacks come with the region already gripped by a tense stand-off between the US and Iran with Britain warning of the risk of a conflict breaking out 'by accident' in the Gulf.

Tehran has distanced itself from the ship sabotage, warning of 'adventurism' by foreign players to disrupt maritime security.

This afternoon, Iraqi Prime Minister Adel Abdul Mahdi looked to ease the crisis when he revealed he was getting indications from talks with both the United States and Iran that 'things will end well' despite the current ramping up of rhetoric from both sides.

Speaking to journalists at a news conference, Abdul Mahdi said Baghdad was communicating regularly with Tehran and Washington, its two main allies who are themselves enemies, and was trying to reduce tensions.

The incident, in the Gulf of Oman, has sparked fears of a looming military confrontation along the world's most important oil artery following the collapse of the 2015 deal designed to curb Iran's nuclear ambitions.

Saudi and UAE officials have been tight-lipped about the extent of the damage but pictures showed at least one tanker with a hole in its hull. The nature of the sabotage, which happened in heavily patrolled waters where dozens of tankers are moored up, has sparked speculation about the possible use of unmanned vessels, speedboats or even armed drones.

Meanwhile, Spain has said its decision to remove a frigate on training exercises from a US combat fleet that is approaching the Persian Gulf was taken purely for 'technical reasons', the country's defence minister has said.

Iran warns it is 'ready for any eventuality' Iran has warned Donald Trump that its military is 'fully ready for any eventuality' in the Middle East amid spiralling tensions between the two nations. Tehran's ambassador in London told America not to 'test the determination of Iran' as he fired back at warlike threats from the White House. Speaking to Sky News, Hamid Baeidinejad said the White House was making 'theatrical manoeuvres' but accused America of playing a 'dangerous game'. 'Our analysis is that they, at least President Trump, doesn't want to engage in a military confrontation with Iran,' he said. 'But while we have renounced any military escalation I would assure you that the Iranian government and Iranian armed forces are fully ready for any eventuality in the region. 'They [America] should not try to test the determination of Iran to confront any escalation in the region.' Hesameddin Ashena, another key adviser to Iranian leader Hassan Rouhani, told Trump: 'You wanted a better deal with Iran. Looks like you are going to get a war instead. 'That's what happens when you listen to the mustache [a reference to national security adviser John Bolton]. Good luck in 2020!'. Iran also warned of 'false flag' operations designed to lure the U.S. into a war. Advertisement

Margarita Robles insisted the decision was 'not an expression of distaste' over the crossing into the Strait of Hormuz by the fleet headed by the USS Abraham Lincoln aircraft carrier. The US fleet is heading to the Persian Gulf at a time of heightened tensions between Washington and Tehran.

Ms Robles insisted Spain's decision was 'prudent' and 'perfectly admissible' under the terms of a two-year cooperation agreement that placed the Mendez Nunez frigate with the US fleet for advanced training.

The ship and its 215 people on board have headed to Mumbai, India, she added.

'The United States government has embarked on a mission that wasn't scheduled when the agreement was signed,' Ms Robles told reporters during an official trip to Brussels.

She said Spain had never given its blessing for the frigate to go on a mission in the Persian Gulf and that it will return to the US fleet once scheduled operations resume.

She declined to comment over the US's hard-line policy toward Iran but said Spain remains a reliable and committed member of Nato.

This morning, Iranian parliamentary spokesman Behrouz Nemati said the attacks could be blamed on 'Israeli mischief', without providing any details on what role Israel may have played in the incident.

As tensions spiralled today, oil prices moved higher with Brent crude futures at $70.30 a barrel at - up seven cents, or 0.1 per cent, from their last close. U.S. West Texas Intermediate (WTI) crude futures were at $61.11 per barrel, up seven cents, or 0.1 per cent, from their previous settlement.

The tinderbox standoff between Iran and the US escalated even further today after four commercial ships were mysteriously 'sabotaged' off the UAE - adding to fears a conflict involving the two nations is looming. In a further twist today, an oil pipeline was targeted in a wave of drone attacks

Four oil tankers anchored in the Mideast were damaged by what Gulf officials described as sabotage, though satellite images obtained by The Associated Press on Tuesday showed no major visible damage to the vessels. One of the vessels, the Emirati-flagged oil tanker A. Michel, with a containment boom around its stern

This satellite image provided by Maxar Technologies shows the Saudi-flagged oil tanker Al Marzoqa off the coast of Fujairah, United Arab Emirates. It was one of four oil tankers anchored in the Mideast damaged in what Gulf officials described Monday as a 'sabotage' attack off the coast of the United Arab Emirates

The Saudi-flagged oil tanker Amjad, pictured in a satellite image yesterday, was also targeted in the sabotage attacks

The oil tankers were visible in satellite images provided Tuesday to the AP by Colorado-based Maxar Technologies. A boom surrounded the Emirati oil tanker A. Michel, indicating the possibility of an oil leak. The other three, including the Andrea Victory (pictured) showed no visible major damage from above

Pompeo is warned against starting war with Iran 'by accident' Secretary of State Mike Pompeo has been warned about staring a war 'by accident' as he met European leaders in Brussels. Pompeo, who called Iran a 'major destabilising force' in an interview with CNBC, made the stop in Brussels to speak to EU leaders about the threat from Tehran. 'We are very worried about the risk of a conflict happening by accident, with an escalation that is unintended really on either side,' Britain's Foreign Secretary Jeremy Hunt warned. 'Most of all, we need to make sure we don't end up putting Iran back on the path to renuclearisation. Because if Iran becomes a nuclear power, its neighbors are likely to want to become nuclear powers. This is already the most unstable region in the world, and this would be a massive step in the wrong direction.' Britain's Foreign Secretary Jeremy Hunt warned Secretary of State Mike Pompeo of the potential military conflict occurring by 'accident' Pompeo's talks with EU leaders gave them the chance to warn him of their own fears of a conflict. President Donald Trump is seeking to isolate Tehran by cutting off its oil exports after pulling out of the deal. While the European Union shares some U.S. concerns about Iran, it still backs the 2015 nuclear deal, saying that it is in Europe's own security interests. 'We are very worried about a conflict, about the risk of a conflict ... of an escalation that is unintended,' Britain's Jeremy Hunt said ahead of talks with Pompeo. Britain, Germany and France's foreign ministers were holding separate meetings in Brussels with Pompeo, who cancelled a planned stopover in Moscow in order to brief the European allies on Washington's latest moves. The U.S. State Department billed Monday's talks in Brussels as a chance 'to discuss recent threatening actions and statements' by Iran. German Foreign Minister Heiko Maas said he had told Pompeo during their Monday meeting: 'We do not want it to come to a military conflict.' It was clear that Europe and the United States were 'going about it in different ways ... taking different courses,' he said. Advertisement

Shipping experts, meanwhile, have warned of the threat of conflict amid fears shipping lanes in the Gulf could become flashpoints as tinderbox relations between the US, its Allies and Iran boil over.

Svetlana Lobaciova, from Gibson Shipbrokers, told the Financial Times: 'We are worried that there could be some military escalation in the Strait of Hormuz that could affect exports out of the region.

'But, at this stage, we do not know what exactly has happened and how significant this is.'

The executive director at the UAE's National Media Council, Jaber Al Lamki said the incident was 'an attempt to sabotage not just boats, but one aimed at undermining global oil supplies and maritime security.'

But a senior Iranian lawmaker and head of parliament's national security committee, Heshmatollah Falahatpisheh, suggested Gulf states were to blame for turning the region into a military zone.

He told state news agency IRNA: 'There are groups whose interests lay in making the region insecure. Iran and the US need to agree on a red line... so that third parties cannot exploit the situation.'

Citing heightened tensions in the region, the United Nations called on 'all concerned parties to exercise restraint for the sake of regional peace, including by ensuring maritime security' and freedom of navigation, U.N. deputy spokesman Farhan Haq said.

The scale of the alleged sabotage remains unclear. A statement from Saudi Energy Minister Khalid al-Falih said two of the kingdom's oil tankers, including one due to later carry crude to the U.S., sustained 'significant damage.'

However, a report from Sky News Arabia, a satellite channel owned by an Abu Dhabi ruling family member, showed the allegedly targeted Saudi tanker Al Marzoqah afloat without any apparent damage.

The oil tankers were visible in satellite images provided to the AP by Colorado-based Maxar Technologies. A boom surrounded the Emirati oil tanker A. Michel, indicating the possibility of an oil leak. The other three showed no visible major damage from above.

Intertanko, an association of independent tanker owners and operators, said it had seen images showing that 'at least two ships have holes in their sides due to the impact of a weapon'.

The U.S. had earlier warned ships that 'Iran or its proxies' could be targeting maritime traffic in the region, and America has moved additional ships and aircraft into the region.

The incident comes after months of increasing diplomatic and economic pressure on Iran, which the U.S. accuses of threatening American interests and allies in the region, including Saudi Arabia and the UAE.

Secretary of State Mike Pompeo on Sunday called Iran a 'major destabilizing force' in the Middle East while Britain warned of the danger of a war being started in the Gulf by accident.

Saudi Arabia has condemned 'acts of sabotage' in the Gulf but the scale of the damage remains unclear.

The country's energy minister Khalid al-Falih said the kingdom's two oil tankers, including one due to carry crude oil to the U.S., sustained 'significant damage' off the coast of Fujairah.

However, a report from Sky News Arabia showed the allegedly targeted Saudi tanker Al Marzoqah afloat without any apparent damage.

The MT Andrea Victory, another of the allegedly targeted ships, sustained a hole in its hull just above its waterline from 'an unknown object,' its owner said.

Pictures of the Andrea Victory, which the company said was 'not in any danger of sinking,' showed damage similar to what the firm described.

An unnamed official has said each ship has a hole between five and ten foot in it, near or just below the water line with an American military team's initial assessment that Iran or Iranian-backed proxies used explosives charges to carry out the attacks on Sunday off the UAE. Pictured is the A Michel, with a containment boom in the water around the hull

The crude oil tanker, Amjad, pictured yesterday which was one of two reported tankers that were damaged in mysterious 'sabotage attacks', off the coast of the Gulf emirate of Fujairah

UAE Navy boats next to Al Marzoqah Saudi Arabia tanker are seen off the Port of Fujairah on Monday afternoon

Al Marzoqah is a large oil tanker which is registered in Saudi Arabia. Pictured: Media taking shots of the vessel on Monday

An Emirati coast guard vessel passes an oil tanker off the coast of Fujairah in the wake of the incident on Monday

Ships anchored at main port of Fujairah on Monday, where media reports initially suggested four boats had been sabotaged by 'explosions'. The UAE later denied this was the case

US Secretary of State Mike Pompeo (pictured yesterday in Brussels) has scrapped a planned visit to Moscow to head to Brussels instead for talks with European officials on Iran

Plan to deploy 120,000 troops to the Middle East if Iran attacks American forces The White House is reportedly planning to deploy 120,000 troops to the Middle East if Iran attacks American forces in an alarming echo of the Iraq War. Acting Defense Secretary Patrick Shanahan presented the plan at a meeting of Donald Trump's top security aides on Thursday, reports the New York Times. Acting Defense Secretary Patrick Shanahan, pictured, presented the plan at a meeting of Donald Trump's top security aides on Thursday Several plans were detailed, the Times said, and 'the uppermost option called for deploying 120,000 troops, which would take weeks or months to complete' - and would be approaching the size of the force that invaded Iraq in 2003. These plans do not call for a land invasion of Iran, which would require far more troops. The Times said among those attending the Thursday meeting were Trump's national security adviser John Bolton, CIA Director Gina Haspel, Director of National Intelligence Dan Coats, and Chairman of the Joint Chiefs of Staff General Joseph Dunford. Advertisement

Emirati officials identified the third ship as the Saudi-flagged oil tanker Amjad. Ship-tracking data showed the vessel still anchored off Fujairah, apparently not in immediate distress.

The fourth ship was the A. Michel, a bunkering tanker flagged in Sharjah, one of the UAE's seven emirates.

The Saudi minister said the attacks on the two Saudi tankers happened at 6am on Sunday.

He said 'the attack didn't lead to any casualties or oil spill,' though he acknowledged it affected 'the security of oil supplies to consumers all over the world.'

One U.S. official said: 'This is what Iran does ... The sort of thing you could see Iran doing ... It fits their MO [modus operandi].'

Emirati officials have declined to elaborate on the nature of the sabotage or say who might have been responsible.

Reports in Lebanon and Iran had earlier claimed there were explosions near the UAE port but there has been no evidence to support their claims.

The apparent attacks come after the U.S. warned ships that 'Iran or its proxies' could be targeting maritime traffic in the region.

Washington has yet to officially respond to the claims of sabotage, although the U.S. energy department said it was monitoring world oil markets.

American naval investigators are also believed to be helping the UAE with their inquiries.

Meanwhile the general-secretary of the six-nation Gulf Cooperation Council described the alleged sabotage as a 'serious escalation' in an overnight statement.

'Such irresponsible acts will increase tension and conflicts in the region and expose its peoples to great danger,' Abdullatif bin Rashid al-Zayani said.

Bahrain, Egypt and the internationally recognized government of Yemen have also condemned the alleged sabotage.

Iran's Foreign Ministry called the incidents 'worrisome and dreadful' and asked for an investigation into the matter.

A senior Iranian lawmaker said 'saboteurs from a third country' could be behind it, after saying on Sunday the incident showed the security of Gulf states was fragile.

Speaking earlier, Britain's Foreign Secretary Jeremy Hunt said the UK was 'very worried about the risk of a conflict happening by accident, with an escalation that is unintended really on either side'.

The alleged sabotage of the merchant ships comes as aircraft carrier USS Abraham Lincoln and B-52 bombers are deployed to bolster the American Navy's grip on the region

A handout photo made available by the US Navy showing an F/A-18F Super Hornet from the 'Jolly Rogers' of Strike Fighter Squadron (VFA) 103 launching off the flight deck of the Nimitz-class aircraft carrier USS Abraham Lincoln

The aircraft carrier strike group is being deployed to the Persian Gulf to counter an alleged but still-unspecified threat from Iran

European leaders are warning of the risk of military conflict between the U.S. and Iran

In this Friday, May 10, 2019 photo released by the U.S. Navy, logistics specialists attach cargo to an MH-60S Sea Hawk helicopter on the flight deck of the Nimitz-class aircraft carrier USS Abraham Lincoln in the Persian Gulf

Yemen's bloody civil war Yemen plunged into civil war in 2014 when Iran-backed rebels captured the capital, Sanaa. A Saudi-led coalition entered the war in March 2015 to help government troops facing the Houthi advance. The U.S. supported the coalition for years despite its airstrikes killing civilians, and is only recently beginning to step back after the October killing of Washington Post columnist Jamal Khashoggi at the Saudi Consulate in Istanbul by Saudi agents. Saudi Arabia and the UAE are leading the Western-backed Sunni Muslim alliance against the Houthis to try to restore the internationally recognised government ousted from power in the capital Sanaa in late 2014. The conflict is widely seen in the region as a proxy war between Saudi Arabia and Iran. The Houthis deny being puppets of Iran and say their revolution is against corruption. Advertisement

Fujairah's port is about 140 kilometers (85 miles) south of the Strait of Hormuz, the narrow mouth of the Persian Gulf through which a third of all oil at sea is traded.

Washington's Energy Information Administration has called the Strait of Hormuz 'the world's most important oil transit chokepoint'.

In recent days the U.S. has warned ships that 'Iran or its proxies' could be targeting maritime traffic in the region.

The US has already strengthened its military presence in the region, including deploying a number of strategic B-52 bombers and the USS Abraham Lincoln strike group in response to alleged Iranian threats.

America is also sending USS Arlington, carrying Marines, as well as a Patriot missile defense system.

The USS Kearsarge, an amphibious assault ship carrying Marines and warplanes, has just left the Persian Gulf and is nearby in the Arabian Sea.

Pompeo scrapped a planned visit to Moscow and headed to Brussels instead for talks with European officials on Iran.

Tensions have flared up again in recent days since Iranian leader Hassan Rouhani warned his country could begin ramping up uranium enrichment if a controversial 2015 deal was not rewritten.

Trump last year withdrew America from the 2015 nuclear deal and restored US sanctions that have pushed Iran's economy into crisis.

Tehran has demanded that the UK, France, Germany, China and Russia help Iran to dodge U.S. sanctions.

A map of the region near the UAE coast where four ships, including two Saudi Arabian tankers, have been sabotaged

European powers have tried to find ways to blunt the impact of new U.S. sanctions, in the hope of persuading Tehran to continue to abide by the deal.

However, their efforts have largely failed, with all major European companies abandoning plans to do business with Iran for fear of U.S. punishment.

Rouhani said last week that Iran would ramp up nuclear enrichment if fresh help did not materialize.

White House defense aide Tim Morrison condemned Iran's attempted 'nuclear blackmail of Europe' and warned: 'Expect more sanctions soon. Very soon.'

Rouhani's comments also sparked outrage in Europe, as Britain warned of 'consequences' if Iran gives up its nuclear commitments.

The threat also sparked a backlash from Israel, where Benjamin Netanyahu warned he would 'not allow Iran to obtain nuclear weapons'.

The sabotaged tankers Tanker Length Year built Owned by A Michel 109m 1998 UAE Andrea Victory 183m 2005 Norway Amjad 330m 2017 Saudi Arabia Al Marzoqah 244m 1999 Saudi Arabia Advertisement

Netanyahu, who has accused Iran of breaching the deal, said Israel 'will continue to fight those who seek to take our lives'.

Secretary of State Mike Pompeo yesterday changed the schedule for his latest trip to Europe, replacing a stop in Moscow for one in Brussels to discuss Iran.

We are very worried about the risk of a conflict happening by accident, with an escalation that is unintended really on either side,' Britain's Foreign Secretary Jeremy Hunt warned.

'Most of all, we need to make sure we don't end up putting Iran back on the path to renuclearization.

'Because if Iran becomes a nuclear power, its neighbors are likely to want to become nuclear powers. This is already the most unstable region in the world, and this would be a massive step in the wrong direction.'

The U.S. State Department billed Monday's talks in Brussels as a chance 'to discuss recent threatening actions and statements' by Iran.

German Foreign Minister Heiko Maas said he had told Pompeo during their Monday meeting: 'We do not want it to come to a military conflict.'

It was clear that Europe and the United States were 'going about it in different ways ... taking different courses,' he said.

Could Gulf tensions lead to Iran-US conflict? Analysts say guerrilla warfare would be more likely than full-scale battles

A surge of tensions in the Gulf has shown the risk of a military confrontation between arch-foes Iran and the United States, even if any conflict would likely be marked by guerrilla warfare rather than full-scale battles, analysts say.

A series of mysterious attacks on ships off the coast of the United Arab Emirates, the key ally of Tehran's Gulf rival Saudi Arabia, prompted President Donald Trump to warn Iran would 'suffer greatly' if it harmed US interests.

The United States and Iran have had no diplomatic relations since the seizure by Iranian radicals of American embassy staff in the wake of the 1979 Islamic revolution.

The two sides have at times been close to conflict - in particular during a tense period under former US president George W. Bush - but analysts see a series of factors as making the current moment particularly combustible.

Trump dismayed European allies by pulling out of the 2015 deal on Iran's nuclear programme unilaterally and is now ratcheting up the rhetoric against Tehran.

Iran and Saudi Arabia, a close ally of the United States for decades, are both enmeshed on opposing sides in the conflict in Yemen. And in US ally Israel, which Iran refuses to recognise, Prime Minister Benjamin Netanyahu is pushing for a hard line against Iran.

'The Trump administration has significantly increased tensions in the region and has therefore increased the odds of some sort of inadvertent or even deliberate military clash with Iran,' said International Crisis Group (ICG) Iran project director Ali Vaez.

'The odds of a clash occurring, even without provocation, are quite high.' he told AFP.

He said a belief on both sides that the other does not want a conflict 'creates plenty of room for miscalculation' especially at a time when both sides have no direct communication channels.

The war in Yemen also intensifies the risk of an incident between Iran and Saudi Arabia - such as an attack by Tehran-backed Huthi rebels on Saudi interests - being magnified and then pulling in the United States.

Drone attacks on Tuesday, claimed by Iran-aligned Yemen rebels, shut down one of Saudi Arabia's main oil pipelines, further ratcheting up Gulf tensions.

There are 'a lot of non-state actors in the region who could take steps that would push the two sides into a direct confrontation,' said Vaez.

But Washington and its Gulf allies have so far stopped short of blaming Tehran for damage to four ships, including two Saudi oil tankers, a Norwegian tanker and an Emirati ship.

Iran has also distanced itself from the incidents, condemning 'acts of sabotage' and a 'criminal act'.

Denis Bauchard, advisor for the Middle East at the French Institute of International Relations (IFRI), said there were elements on all sides who wanted no further escalation.

'Looking at this rationally, this should not go any further as there are people who want to calm this down,' he said, pointing to the US and Israeli military establishment.

He said that Iran had so far kept a notably 'low profile' in the current tensions but a risk came from hawks on both sides such as US national security advisor John Bolton in the United States and the Revolutionary Guards in Iran.

Any escalation between the United States and Iran would likely be played out at sea and have immediate global implications for energy markets if it affected shipping in the key transit point of the Strait of Hormuz.

Analysts say that in the event of a conflict, Iran would most likely resort to its tried and trusted strategy of asymmetric warfare which it has seen since the 1980-1988 Iran-Iraq war as the best way to outflank a more powerful enemy.

'A US-Iran war wouldn't be a naval war at all in the strict sense of the term,' said James Holmes, from the Naval War College in the United States.

'Guerrilla warfare, not the traditional sea fight, makes a better analogy for Iranian maritime strategy,' he said, adding Iranian ships would concentrate firepower in narrow parts in the Strait of Hormuz.

Jean-Sylvestre Mongrenier, researcher at the Franco-Belgian think-tank Institut Thomas More, said Iran is well aware it has no match for the aircraft carriers of the United States.

He said Iran would not aim to inflict a naval defeat on the United States, but make clear its engagement in the Gulf has a military and material cost.

Such actions could include placing mines in the Strait of Hormuz, harassing US navy craft with smaller warships and also using anti-ship missiles, he said.