LONDON: Three Iranian vessels tried to block the passage of a BP-operated tanker through the Strait of Hormuz but withdrew after warnings from a British warship, the British government said on Thursday. The stand off followed a warning by U.S. President Donald Trump that U.S. sanctions on Iran would soon be “substantially” increased as part of Washington’s drive to curb Iran’s nuclear activities and regional behavior. Britain urged Iran to “de-escalate the situation in the region” after the incident involving British Heritage, which is operated by BP (BP.L) under an Isle of Man flag.

“HMS Montrose was forced to position herself between the Iranian vessels and British Heritage and issue verbal warnings to the Iranian vessels, which then turned away,” a British government spokesman said in a statement. The incident came almost a week after British Royal Marines boarded an Iranian tanker, the Grace 1, off Gibraltar and seized it on suspicion that it was breaking EU sanctions by taking oil to Syria.

Iran’s armed forces chief of staff, Major General Mohammad Bagheri, had said the British seizure would not go unanswered but the Islamic Republic denied it had sought to stop the British Heritage. Iranian Foreign Minister Mohammad Javad Zarif dismissed the British report as “worthless”, according to the semi-official Fars news agency. (Agencies)