A British-flagged tanker and another vessel linked to the UK were seized in the Strait of Hormuz on Friday, according to a statement from the UK foreign secretary Jeremy Hunt. Hunt said he would be attending an emergency government meeting to establish the facts and try to “swiftly secure” the vessels’ release. The British-flagged tanker — Stena Impero — was “approached by unidentified small crafts and a helicopter during transit of the Strait of Hormuz”, the company that owns the tanker, Stena Bulk, said. Stena Bulk and the one that manages the tanker, Northern Marine Management, said they were “unable to contact the vessel which is now heading north towards Iran”. Stena Impero had 23 people aboard but the foreign office said that there were “no British citizens on board either ship”. The Iranian Revolutionary Guard (IRGC) said in a statement they had seized the British-flagged tanker due to “violating international regulations”. “After it was seized it was transferred to Iranian shores to undergo legal procedure,” the IRGC said. The second vessel was Liberian-flagged, the UK foreign office said. “Our Ambassador in Tehran is in contact with the Iranian Ministry of Foreign Affairs to resolve the situation and we are working closely with international partners,” Hunt said in a statement on Friday night. “These seizures are unacceptable. It is essential that freedom of navigation is maintained and that all ships can move safely and freely in the region.” Relations between Iran and the West have been increasingly strained after Britain seized an Iranian tanker in Gibraltar on suspicion of smuggling oil to Syria in breach of European Union sanctions. “We are urgently seeking further information and assessing the situation following reports of an incident in the Gulf,” a spokesman for Britain’s Ministry of Defence said on Friday. Three Iranian vessels tried to block a British-flagged oil tanker in the Strait of Hormuz last week. The royal navy had escorted the oil vessel through the Strait. The UK defence secretary Penny Mordaunt said in a statement last week that the government urged “Iranian authorities to de-escalate the situation”. Tensions between Iran and the United States and its allies have risen since Washington imposed new sanctions against Iran as part of a “maximum pressure” campaign. Iran has responded by scaling back its commitments under the 2015 nuclear deal. The Strait of Hormuz is a key strategic location for the global oil trade.