A ransom of up to $1billion paid by Qatar to Iranian and Al Qaeda-linked forces in Syria to release kidnapped members of the country's royal family may have been a trigger behind six nations' cutting ties with Doha, officials have claimed.

The hefty ransom reportedly secured the release of 26 members of a falconry party, which included some members of Qatar's royal family, who were kidnapped by jihadis while hunting in southern Iraq in December 2015.

Saudi Arabia, Egypt, United Arab Emirates and Bahrain cut diplomatic relations with Qatar on Monday over alleged support for Islamists and Iran in a coordinated move.

Yemen, Libya's eastern-based government and the Maldives joined in later - opening up one of the worst rifts in years.

It was revealed on Monday that one of the tipping points for Qatari-Gulf Arab relations could have been a ransom Qatar officials paid earlier this year. The hefty ransom reportedly secured the release of 26 members of a falconry party (pictured above), which included some members of Qatar's royal family

The 26 members of the hunting party were kidnapped by jihadis while hunting in southern Iraq in December 2015

The biggest diplomatic crisis in the Persian Gulf region since the 1991 US-led war against Iraq pits several nations against Qatar, which is home to some 10,000 American troops and a major US military base.

It was revealed on Monday that one of the tipping points for Qatari-Gulf Arab relations could have been a ransom Qatar officials paid earlier this year.

Qatar paid the ransom to al-Qaeda affiliate fighting in Syria and Iranian security officials, a person involved in ransom negotiations said in April.

The incident was sparked when the group was kidnapped December 16, 2015 from a desert camp for falcon hunters in southern Iraq.

They had legally entered Iraq to hunt inside Muthanna province, some 230 miles (370 kilometers) southeast of the Iraqi capital, Baghdad. Shiite militias are active in that area and work closely with the neighboring Shiite power Iran.

A person involved in the ransom negotiations said in April that 11 of the captives were members of Qatar's Al Thani ruling family.

He also said Qatar paid tens of millions of dollars to Shiite groups, and to the al-Qaida-linked Levant Liberation Committee and Ahrar al-Sham, which are involved in the population transfers underway in Syria.

Both groups were part of an armed opposition alliance that swept through Syria's Idlib province, seizing it from government control in 2015.

Qatar says it does not support extremist groups in Syria or elsewhere, despite aggressive efforts to back Sunni rebel groups fighting to oust the Syrian government, which is backed by Iran and Russia.

Qatar paid the ransom to al-Qaeda affiliate fighting in Syria and Iranian security officials, commanders of militant groups and government officials in the region claimed. Pictured above, Qatar's Emir Sheikh Tamim bin Hamad Al-Thani (pictured in 2014) attends a Gulf Cooperation Council summit in Doha, Qatar

The group of Qatari hunters, which included members of the royal family, were snatched from their camp near Samawah province, 230 miles from Baghdad

Donald Trump referenced Saudi Arabia cutting ties with Qatar on Twitter, saying that his meeting with 'with the King and 50 countries' was 'already paying off'.

Trump suggested in his tweet that the decision from six nations to cut ties with Saudi Arabia could be the 'beginning of the end of terrorism'

The country's ambitious foreign policy efforts haven't always succeeded. Gulf neighbors withdrew their ambassadors in 2014 over Qatar's support for the Muslim Brotherhood group in Egypt, where the group was ousted.

The deal to release the group was reached in April and again heightened concerns among Arab nations that Qatar supports terrorist groups.

'The ransom payments are the straw that broke the camel's back,' one Gulf observer told the the Financial Times.

Qatar has denied that it supports terrorist groups and said in a statement on Monday that its neighbors' decision to cut ties was 'founded on allegations that have no basis in fact'.

Kuwait is now trying to mediate a diplomatic crisis in which Arab countries have cut diplomatic ties to Qatar and moved to isolate the energy-rich, travel-hub nation from the outside world, Qatar's foreign minister said.

The United Arab Emirates said on Tuesday that Qatar would need to provide a 'guaranteed roadmap' before it would consider mending ties.

Since Monday, airlines suspended flights and residents nervous about the peninsula's lone land border closing cleaned out grocery store shelves.

Videos of Qatar's borders show traffic jams as residents try to return to the country from Saudi Arabia.

A ban on Qatari flights imposed by Saudi Arabia and its allies took effect Tuesday as first efforts were made to resolve the biggest feud to hit the Arab world in years.

The Gulf states and Egypt banned all flights to and from Qatar and ordered Qatari citizens to leave within 14 days.

Countries including Saudi Arabia also banned Qatari flights from their airspace and Riyadh closed its land border with Qatar, sparking panic buying in Doha amid fears of food shortages.

This graphic provided by Flight Radar shows how Qatar Airways flights are managing bans on flights through the airspace of Bahrain, Saudi Arabia, UAE, & Egypt, by flying over Iranian airspace

Hamad International Airport (HIA) in Doha, Qatar, was filled with passengers of canceled flights on Tuesday

Six nations severed diplomatic ties with Qatar on Monday. Pictured above, passengers of cancelled flights wait in Hamad International Airport (HIA) in Doha

The decision by Saudi Arabia and other countries to cut ties with Qatar moved to isolate the energy-rich nation that is home to a major U.S. military base, accusing it of supporting terrorist groups and backing Iran

Qatar says it does not support extremist groups in Syria or elsewhere, despite aggressive efforts to back Sunni rebel groups fighting to oust the Syrian government, which is backed by Iran and Russia. Pictured above, passengers of cancelled flights wait in Hamad International Airport (HIA) in Doha on Monday

The first concrete effects were being seen on Tuesday morning, with the flight ban causing delays and cancellations.

UAE carriers Emirates, Etihad, flydubai and Air Arabia, as well as Saudi Airlines had all announced the suspension of flights to and from Qatar as of Tuesday morning.

A total of 27 flights from Dubai to Doha had been scheduled for Tuesday and the Dubai Airports website showed all flights to Doha cancelled.

Qatar Airways, for its part, said it had suspended all flights to Saudi Arabia, the UAE, Bahrain and Egypt 'until further notice'.

Saudi Arabia also announced it was revoking Qatar Airways' operating license.

Doha's Hamad International Airport was virtually deserted early on Tuesday. More than 30 flights were shown cancelled on airport television screens and the departures hall was eerily quiet.

On Monday, shoppers had flooded Doha's supermarkets worried that food imports would dry up.

In one store queues were up to 25-people deep as shoppers piled trollies high with supplies from rice to nappies.

'It's a cycle of panic and I needed to get pasta,' said Ernest, a Lebanese national pushing two trollies.

In an interview with Doha-based satellite news network Al-Jazeera, foreign minister Sheikh Mohammed Bin Abdulrahman Al Thani said Kuwait's ruler had asked Qatar's ruling emir, Sheikh Tamim bin Hamad Al Thani, to hold off on giving a speech about the crisis late on Tuesday night.

'He received a call from the emir of Kuwait asking him to postpone it in order to give time to solve the crisis,' Sheikh Mohammed said.

A ban on Qatari flights imposed by Saudi Arabia and its allies took effect Tuesday as first efforts were made to resolve the biggest feud to hit the Arab world in years

The Gulf states and Egypt banned all flights to and from Qatar and ordered Qatari citizens to leave within 14 days

Countries including Saudi Arabia also banned Qatari flights from their airspace and Riyadh closed its land border with Qatar, sparking panic buying in Doha amid fears of food shortages

UAE carriers Emirates, Etihad, flydubai and Air Arabia, as well as Saudi Airlines had all announced the suspension of flights to and from Qatar as of Tuesday morning. Pictured above, people gather outside a branch of Qatar Airways in the United Arab Emirate of Abu Dhabi

Still, the minister struck a defiant tone, vowing his nation rejected those 'trying to impose their will on Qatar or intervene in its internal affairs'.

Kuwait and Oman did not join fellow members of the Gulf Cooperation Council (GCC), which also includes Qatar, in cutting ties with Doha.

Kuwait's state-run news agency KUNA confirmed the phone call and said the Kuwaiti emir had also received a top Saudi envoy in an apparent mediation effort.

'Efforts aimed at containing tensions in the relations between brothers' were discussed in the phone call, KUNA said.

Turkey, which has good relations with Qatar and other Gulf states, also offered to help and Turkish President Recep Tayyip Erdogan late on Monday spoke to the emirs of Qatar and Kuwait and to Saudi King Salman.

Algeria expressed 'deep concern' on Tuesday after several Arab states cut diplomatic ties with Qatar, appealing to the countries involved to resolve their differences through dialogue.

'While calling on all the countries concerned to adopt dialogue ... Algeria appeals for the need to observe, in all circumstances, the principles of good neighbourliness and non-interference in the internal affairs of states,' said a foreign ministry statement carried by state news agency APS.

It said Algeria remained confident that the current rift would be temporary, despite 'real challenges' to Arab unity and solidarity, 'not least terrorism'.

The move from six Arab countries to cut ties with Qatar came just two weeks after US president Donald Trump visited Saudi Arabia and vowed to improve ties with both Riyadh and Cairo to combat terrorism and contain Iran.

Trump spoke of the decision from six nations to cut ties with Qatar on Twitter on Tuesday.

'So good to see the Saudi Arabia visit with the King and 50 countries already paying off,' he wrote. 'They said they would take a hard line on extremism, and all reference was pointing to Qatar.

'Perhaps this will be the beginning of the end of the horror of terrorism!'

The United Arab Emirates and Saudi Arabia have also stopped exports of white sugar to Qatar, in the first sign that the diplomatic crisis is hitting food trade, trade sources said on Monday

In this photo provided by Doha News, shoppers stock up on supplies at a supermarket in Doha, Qatar on Monday

Local media in Qatar reported there was already some panic buying as people stock up on food

People stocked up on bottled water, milk and bread products after GCC allies cut their ties with Qatar

Qatar is dependent on the UAE and Saudi Arabia for its white sugar imports, which are estimated at less than 100,000 tonnes annually. The announcement that six countries have severed diplomatic ties could lead to food shortages in Qatar, analysts have warned

US secretary of state Rex Tillerson said the move was rooted in long-standing differences and urged the parties to resolve them.

Football's governing body Fifa said it remained in regular contact with Qatar, which will host the 2022 World Cup. It did not elaborate.

Saudi Arabia said it was cutting ties due to Qatar's 'embrace of various terrorist and sectarian groups aimed at destabilising the region', including the Muslim Brotherhood, al Qaida, the Islamic State group and militants supported by Iran in the kingdom's restive Eastern Province.

Egypt's foreign ministry accused Qatar of taking an 'antagonist approach' toward Cairo and said 'all attempts to stop it from supporting terrorist groups failed'.

Qatar long has denied funding extremists, though Western officials have accused Qatar of allowing or even encouraging funding of Sunni extremists like al Qaida's branch in Syria, once known as the Nusra Front.

The Gulf countries ordered their citizens out of Qatar and gave Qataris abroad 14 days to return home to their peninsular nation, whose only land border is with Saudi Arabia. The countries also said they would eject Qatar's diplomats.

The nations also said they planned to cut air and sea traffic. Doha-based satellite news network Al-Jazeera reported trucks carrying food had begun lining up on the Saudi side of the border, apparently stranded.

The Qatar Stock Exchange fell more than 7 per cent in trading on Monday.

Qatar Airways, one of the region's major long-haul carriers, has suspended all flights to Saudi Arabia, the United Arab Emirates, Egypt and Bahrain until further notice.

Saudi Arabia licences and shut down all of the airline's offices in the country, according to a statement from the state news agency.

The United Arab Emirates and Egypt have announced they will be cutting all official ties with Qatar. Pictured left to right are UAE president Sheikh Khalifa bin Zayed al-Nahayan and Egypt's Abdel Fattah el-Sisi

They are joining Bahrain and Saudi Arabia, both of whom had already denounced the country. Pictured are King Hamad Bin Isa Al Khalifa of Bahrain, left, and King Salman bin Abdulaziz al-Saud (right) of Saudi Arabia

Yemen has also cut ties with Qatar. Pictured above, Yemeni President Abdrabbuh Mansur Hadi in March

On its website, the carrier said the suspension of its flights would take effect on Tuesday and customers are being offered a refund.

The route between Doha, Qatar and Dubai is popular among business travellers and both are major transit hubs for travellers between Asia and Europe.

FlightRadar24, a popular airplane tracking website, said Qatar Airway flights already had started to be affected.

'Many of Qatar Airways' flights to southern Europe and Africa pass through Saudi Arabia,' the site said. 'Flights to Europe will most likely be rerouted through Iran and Turkey.'

Qatar, which has a population of 2.5 million people, is facing potential food shortages as people scramble to buy up food at grocery stores across the country.

The country is largely dependent on imports of foodstuffs to meet its needs. It imports approximately 90 per cent of its food, with 40 per cent of it coming solely from Saudi Arabia.

Trade sources, who declined to be named, said the UAE and Saudi Arabia had stopped exports of white sugar to Qatar.

Qatar is dependent on the UAE and Saudi Arabia for its white sugar imports, which are estimated at less than 100,000 tonnes annually.

The crisis also comes after U.S. President Donald Trump's recent visit to Saudi Arabia for a summit with Arab leaders (pictured on May 21). Since the meeting, unrest in the region has grown

Consumption is traditionally higher during the Muslim holy month of Ramadan, which is currently being observed.

'There will be shortages of food, certain things will be hard to find,' Christian Henderson, a Middle Eastern food expert at SOAS University in London, told Gulf News.

Dairy, meat and vegetables are expected to be heavily impacted.

'Supplies of sugar have been stopped and there is no indication when they could resume,' one Middle East based trade source said.

Photos on social media have shown Qatar residents queuing up at grocery stores and emptying shelves.

'Panic buying always makes things worse, and prices will go up,' Henderson said.

Qatar's cabinet said earlier on Monday it was still open for trade.

'The Council would like to reassure Qatar´s citizens and residents that the government had already taken the necessary measures and precautions to ensure that normal life continues, and that there will be no negative impact caused by the latest measures,' the Qatari government said in a statement.

Meanwhile, the Qatari currency came under pressure on Tuesday as Gulf commercial banks began to hold off on dealing with Qatari banks because of the diplomatic rift in the region, banking sources told Reuters.

The United Arab Emirates and Egypt announced they will be joining Bahrain and Saudi Arabia and withdrawing their diplomatic staff from Qatar, a gas-rich nation that will host the 2022 FIFA World Cup (pictured are World Cup preparations)

Some Saudi Arabian, United Arab Emirates and Bahraini banks were delaying business with Qatari banks, such as letters of credit, after their governments cut diplomatic ties and transport links with Doha on Monday, accusing Qatar of supporting terrorism.

Saudi Arabia's central bank advised banks in the kingdom not to trade with Qatari banks in Qatari riyals, the sources said. The central bank did not respond to a request for comment.

Qatari banks have been borrowing abroad to fund their activities. Their foreign liabilities ballooned to 451 billion riyals ($124 billion) in March from 310 billion riyals at the end of 2015, central bank data shows.

So any extended disruption to their ties with foreign banks could be awkward, though the government of the world's biggest natural gas exporter has massive financial reserves which it could use to support them.

Banks from the United Arab Emirates, Europe and elsewhere have been lending to Qatari institutions.

Gulf banking sources who declined to be named because of political sensitivities said Saudi Arabian, UAE and Bahraini banks were postponing deals until they received guidance from their central banks on how to handle business with Qatar.

'We will not take action without central bank guidance, but it is wise to evaluate what you give to Qatari clients and hold off until there is further clarity,' said a UAE banker, adding that trade finance had stalled for the time being.

The sources also said the UAE and Bahraini central banks had asked banks under their supervision to report their exposure to Qatari banks. The UAE and Bahraini central banks did not respond to requests for comment.