IRAN’S Revolutionary Guard said it has seized a British oil tanker in the Strait of Hormuz – one of two vessels seized by the nation’s forces.

The 183-metre Stena Impero was “approached by unidentified small crafts and a helicopter during transit,” according to the owners Stena Bulk. They added: “There are 23 seafarers aboard. There have been no reported injuries and their safety is of primary concern to both owners and managers.”

Northern Marine Management Limited, the Scotland-based operator of Stena Imperio, said they “had not been able to establish contact directly with the vessel since it was notified of the incident”.

Tasnim news agency, the Iranian Ports and Maritime Organisation, said: “We received some reports on the British oil tanker, Stena Impero, causing problems.

“We asked the military forces to guide this tanker towards Bandar Abbas port to have the required investigations carried out.”

Iranian semi-official news agency Fars cited the Islamic Revolutionary Guard Corps (IRGC), saying that it was “not following international maritime regulations,” which resulted in the seizure. At the time of the interception, Stena Bulk disputed the claim, saying the ship was travelling through international waters.

Based on marine traffic tracking information, the vessel departed from Fujairah port at 9.20am yesterday in the Strait of Hormuz. The second tanker seized was the British-operated, Liberian-flagged MV Mesdar, according to an official from the US. MV Mesdar is owned by British company Norbulk Shipping UK Ltd.

Tracking shows that both ships sharply changed direction to head North towards Iran.

The UK Chamber of Shipping has “condemned unreservedly” the capture of the Stena Impero.

CEO Bob Sanguinetti said: “The action by those involved is in violation of international regulations which protect ships and their crews as they go about their legitimate business in international waters.

“Our priority is for the safety and welfare of the crew. We call on the UK Government to do whatever is necessary to ensure their safe and swift return.”

He described the incident as an “escalation”, saying: “Whilst we call for measured response, it is also clear that further protection for merchant vessels must be forthcoming to ensure enhanced security to guarantee free flow of trade in the region.”

Britain’s Government Emergency Committee is currently meeting to discuss the incident.

A government spokesman said: “We are urgently seeking further information and assessing the situation following reports of an incident in the Gulf.”

It comes after the US claims that a United States warship destroyed an Iranian drone which was performing a close flyby in the same region.

On Thursday, Trump said the USS Boxer took defensive action after an Iranian drone closed to within 1000 yards of the warship and ignored multiple calls to stand down. Trump blamed Iran for a “provocative and hostile” action and said the US responded in self-defence

Iran’s foreign minister, Mohammad Javad Zarif, told reporters yesterday that “we have no information about losing a drone”.

Yesterday Gibraltar was granted the power to extend its detention of Iran’s Grace 1 oil tanker for a further month. Grace 1 was intercepted by marines off the Gibraltar coast on July 4 after it was suspected that it was in breach of sanctions by smuggling oil to Syria.