Iran has released video of marine commandos seizing a British-flagged tanker in an action which has dramatically escalated tensions between the regime and the UK and its allies.
The footage shows a group of men, all wearing balaclavas, rappelling from a helicopter to the deck of the Stena Imperio on Friday.
Today British Foreign Secretary Jeremy Hunt said Iran's action "raises very serious questions about the security of British shipping and indeed international shipping in the Strait of Hormuz."
Speaking after a meeting of the Government's emergency committee Cobra, Mr Hunt said the vessel was seized in Omani waters in "clear contravention of international law".
The ship, which was carrying no cargo, remains in Iranian hands. Its crew are said to be safe and in good health.
Retaliation for Royal Marines seizing Iranian tanker off Gibraltar on July 4?
Since Royal Marines abseiled from a helicopter off Gibraltar to seize the Grace 1 Iranian tanker on July 4, a number of Iranian officials had threatened to retaliate.
And on Friday Iranian troops seized the tanker, which is owned by Stena Bulk who are based in Sweden.
The vessel was surrounded by four vessels and a helicopter before heading into Iranian waters, according to Mr Hunt.
A spokesman for the Iranian Revolutionary Guards claimed that the UK sent two helicopters to harass Iranian troops as they seized the tanker.
Despite the "resistance and interference" of the British warship, the Stena Impero was brought to the shore, Ramezan Sharif, a Guards spokesman said.
Owners of tanker wish to visit crew members
Stena Bulk are said to be preparing a formal request to visit its 23 crew members who are of Indian, Russian, Latvian and Filipino nationality, Stena said.
Iran claim the tanker violated maritime regulations in the Strait of Hormuz and got into an accident with an Iranian fishing boat. This has been denied by the UK.
It is being held at the Iranian port of Bandar Abbas for investigations.
Iran's semi-official Tasnim news agency posted a video of the ship anchored at sea, its name clearly visible.
Seizure branded a 'hostile act' by Defence Secretary
British Defence Secretary Penny Mordaunt called the incident a "hostile act".
Britain also summoned the Iranian charge d'affaires in London.
The strait, between Iran and the Arabian peninsula, is the sole outlet for exports of the vast majority of Middle Eastern oil, and the seizure sent oil prices sharply higher.
Iran's foreign minister Javad Zarif tweeted that the UK "must cease being an accessory to #EconomicTerrorism of the US".
He said it was Iran that guarantees the security of the Gulf and the Strait of Hormuz.
The United States, which tightened sanctions against Iran in May with the aim of halting its oil exports altogether, has been warning for months of an Iranian threat to shipping in the strait.
France, Germany and the European Union joined Britain in condemning the seizure.
The three big European countries are signatories to a 2015 nuclear deal between Tehran and world powers that Washington undermined by quitting last year, setting Iran's already fragile relations with the West on a downward spiral.
Under the pact, Iran agreed to restrict nuclear work in return for lifting sanctions.
The European countries opposed the Trump administration's decision to abandon the agreement last year, but have so far failed to fulfil promises to Iran of providing alternative means for it to access world trade.
