Friday’s seizure of a British-flagged tanker off Iran's coast came two weeks after the Royal Navy detained an Iranian vessel near its Mediterranean peninsular exclave Gibraltar, further deteriorating already-poor relations between London and Tehran.

The UK government is expected to come under scrutiny for their decision to seize an Iranian oil tanker off Gibraltar two weeks ago, without ensuring that it could protect British-operated vessels sailing through the Strait of Hormuz, according to the Guardian.

Lord West, the former commander of the Royal Navy, said that the UK should not "pretend we're surprised" by the seizure of a British-flagged tanker by Iran’s Revolutionary Guard Corps.

"What I find extraordinary is that we knew that the Iranians would try something like this a few days ago,” he told Sky News.

"I'm absolutely amazed that we haven't implemented some sort of control of red ensign shipping within the region whereby no tanker would go in to what is clearly a dangerous zone without an escort, and I find it bizarre that we seem to have ships doing exactly that."

Market Reacts to the Incidents

US oil prices went up following reports of the tanker's seizure: WTI crude futures rose nearly 0.6 per cent to $55.63 a barrel on Friday, while Brent, the international benchmark, gained 1.7 per cent and was trading at just under $63 a barrel.

What Happened on Friday?

Iran announced on Friday night that it had detained two oil tankers in the Strait of Hormuz – the British-flagged Stena Impero and the Mesdar, registered in Liberia but operated by a UK company.

The Mesdar was allowed to continue its voyage after Iranian forces told it to comply with environmental regulations, Iranian media reported, while the Stena was seized for the alleged violation of maritime rules and taken to an Iranian port.

Its operator, however, said that the 30,000-tonne ship was in international waters and “in full compliance with all navigation and international regulations". There are 3 Russian nationals among the ship’s crew of 23, which also includes nationals of India, Latvia and the Philippines.

How Did the UK React?

The British government held a major emergency meeting to discuss the incident. Foreign Secretary Jeremy Hunt called it “unacceptable” and warned Iran of "serious consequences" if it does not release the tanker.

US President Donald Trump said he would discuss the situation with his UK allies.

The Pentagon announced it was developing a multinational maritime operation to beef up surveillance and security in the region, which will likely involve British forces.

Iranian Tanker in Gibraltar

Tehran is currently urging the release of Iranian supertanker Grace 1, which was intercepted by British forces off the coast of Gibraltar two weeks ago.

Gibraltar authorities claimed there were reasons to believe that the vessel was transporting oil to Syria in breach of EU sanctions, which Iran denied.

Iran's supreme leader Ayatollah Ali Khamenei described the tanker's seizure as an act of "piracy" and warned that the Islamic Republic wouldn’t let it go unanswered.

© AFP 2020 / JORGE GUERRERO A picture shows supertanker Grace 1 off the coast of Gibraltar on July 6, 2019

Last week, the UK claimed that Iranian patrol boats had tried to intercept a British oil tanker in the Gulf, but were turned away by a British warship, the HMS Montrose. Iran has rejected the claims.

The UK has since announced the deployment of two warships in the Gulf in addition to the HMS Montrose, which is permanently stationed in the area.

The recent deterioration of UK-Iran relations comes amid a broader conflict between Tehran and Washington. The US military claimed on Friday that it had shot down an Iranian drone (which Tehran already rebutted), a month after the Revolutionary Guards destroyed a US spy drone that allegedly violated Iran’s airspace.

The ongoing US-Iran confrontation has been deepening for over a year now, since Donald Trump quit the 2015 nuclear deal, claiming that it had failed to curb Iran’s nuclear ambitions and stop it from “sponsoring” terrorism.

The Trump administration went on to slap tough economic sanctions on the oil-rich country in a bid to pressure it into a new accord. Iran has been reluctant to bow to the pressure and had continued to adhere to the deal along with the remaining signatories.

However, the Islamic Republic has accused the world powers of failing to shield it from crippling US sanctions and has recently suspended some of its commitments under the agreement.