Britain says Iran unsuccessfully tried to block its oil tanker

The British government said on Thursday that three Iranian vessels unsuccessfully tried to block the passage of a BP-operated tanker through the Strait of Hormuz.

The UK government said that the Iranian ships on Wednesday only turned away after receiving "verbal warnings" from a UK warship accompanying the commercial vessel British Heritage.

"We are concerned by this action and continue to urge the Iranian authorities to deescalate the situation in the region," the statement said.

“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.

Iran's Foreign Minister Mohammad Javad Zarif rejected the accusation, according to Fars news agency.

"Apparently the British tanker has passed. What they have said themselves and the claims that have been made are for creating tension and these claims have no value," he said.

Tensions between Iran and the US and its allies have risen sharply since Washington last year unilaterally withdrew from a landmark nuclear deal signed between Tehran and world powers in 2015.

Since then, the administration of US President Donald Trump has stepped up economic sanctions against Iran and moved to bring the country's oil exports to zero as part of a "maximum pressure" policy to make it halt actions that it said undermined regional security.

Iran has responded to the sanctions by starting to exceed limits put on its nuclear activities under the 2015 deal.