LONDON • Three Iranian vessels tried to block a BP-operated tanker passing through the Strait of Hormuz, a key waterway for global oil shipments, but backed off when confronted by a Royal Navy warship, the British government said yesterday.
The tanker British Heritage was approaching the northern entrance to the strait when its British naval escort, the HMS Montrose, "was forced to position itself between the Iranian vessels" and the ship, a government statement said.
The navy ship issued "verbal warnings to the Iranian vessels, which then turned away", it added. "We are concerned by this action and continue to urge the Iranian authorities to de-escalate the situation in the region."
The incident followed United States President Donald Trump's warning he would soon "substantially" increase US sanctions on Iran as part of a drive to curb Iran's nuclear programme and force Teheran to change its behaviour in the region.
The US blames Iran for a series of attacks on shipping since mid-May in the world's most important oil artery, accusations that Teheran rejects but which have raised fears the long-time foes could slip into direct military conflict.
The growing confrontation between Iran and the West took another twist last week when British Royal Marines seized an Iranian tanker, the Grace 1, off Gibraltar on suspicion that it was breaking European Union (EU) sanctions by taking oil to Syria.
"The enemy is going to regret this act," Rear-Admiral Ali Fadavi, a deputy Revolutionary Guard commander, said yesterday, Iran's Tasnim News Agency reported.
"They would not have done it if they had done the minimum calculation."
Gibraltar police said yesterday that the Indian captain and chief officer of the Grace 1 have been arrested for breaking EU sanctions, but neither have been charged.
Meanwhile, Iran denied that its forces challenged the British-flagged tanker, operated by the London-based oil and gas company BP.
In a statement carried by Iranian news agencies, Iran's Islamic Revolutionary Guard Corps said there had been no confrontations with foreign vessels in the past 24 hours.
The statement added that the Revolutionary Guard would "act with precision and power" if it received orders to seize any foreign ship in the area, the state-run Islamic Republic News Agency reported.
Iranian Foreign Minister Mohammad Javad Zarif said Britain was trying to "increase tensions" by saying the ship was unable to pass through the strait, calling the government's claims "worthless".
British Foreign Secretary Jeremy Hunt, a contender to succeed Mrs Theresa May as Conservative Party leader and prime minister, said the developments were "very concerning", but that he was "also very proud of the Royal Navy and the role they played in keeping British assets, British shipping, safe".
"We are continuing to monitor the situation very, very carefully," he told the BBC.
A spokesman for Mrs May told reporters that Britain has a "long-standing maritime presence in the Persian Gulf. We are continuously monitoring the security situation there and are committed to maintaining freedom of navigation in accordance with international law".
Tensions in the Gulf have been rising in recent weeks as Iran began to move away from the terms of the 2015 nuclear accord it struck with world powers.
The US withdrew from the pact last year and extended sanctions against Iran, effectively driving Iran from mainstream oil markets and forcing it to find unconventional ways to sell crude.