Iranian boats tried to impede a British oil tanker near the Gulf – before being driven off by a Royal Navy ship, the Ministry of Defence has said.
HMS Montrose, a British frigate shadowing the BP-owned tanker, was forced to move between the three boats and the tanker, a spokesman said.
He described the Iranians’ actions as “contrary to international law”.
Iran had threatened to retaliate for the seizure of one of its own tankers, but denied any attempted seizure.
Boats believed to belong to Iran’s Islamic Revolution Guard Corps (IRGC) approached tanker British Heritage and tried to bring it to a halt as it was moving out of the Gulf into the Strait of Hormuz.
Guns on HMS Montrose were trained on the Iranian boats as they were ordered to back off, US media reported. The boats heeded the warning and no shots were fired.
The BBC has been told British Heritage was near the island of Abu Musa when it was approached by the Iranian boats.
HMS Montrose had been shadowing British Heritage from a distance but came to its aid once the Iranian boats began harassing the tanker, BBC defence correspondent Jonathan Beale said.
Although Abu Musa is in disputed territorial waters, HMS Montrose remained in international waters throughout.
A UK government spokesman said: “Contrary to international law, three Iranian vessels attempted to impede the passage of a commercial vessel, British Heritage, through the Strait of Hormuz.”
Defence Secretary Penny Mordaunt said the government was concerned by the incident and urged the Iranian authorities to “de-escalate the situation”.
Foreign Secretary Jeremy Hunt added the UK would monitor the situation “very carefully”.
Prime Minister Theresa May’s official spokesman said the government was “committed to maintaining freedom of navigation in accordance with international law”.
The relationship between the UK and Iran has become increasingly strained, after Britain said the Iranian regime was “almost certainly” responsible for the attacks on two oil tankers in June.
Last week, British Royal Marines helped the authorities in Gibraltar seize an oil tanker because of evidence it was carrying Iranian crude oil to Syria in breach of EU sanctions.
The Government of Gibraltar said it would not comment on matters relating to the vessel as it was the subject of a police investigation. It said the matter was also now in the Supreme Court.
The Port of Gibraltar’s live map showed the tanker, Grace 1, remained anchored about 3km off the east coast of Gibraltar on Thursday.
An Iranian official said a British oil tanker should be seized if Grace 1 was not released.
Iran also summoned the British ambassador in Tehran to complain about what it said was a “form of piracy”.
On Wednesday, Iranian President Hassan Rouhani mocked the UK, calling it “scared” and “hopeless” for using Royal Navy warships to shadow another British tanker in the Gulf.
HMS Montrose had shadowed British tanker the Pacific Voyager for some of the way through the Strait of Hormuz, but that journey had passed without incident.
“You, Britain, are the initiator of insecurity and you will realise the consequences later,” Mr Rouhani said.
Iran appears to have been attempting to make good on its threat against British-flagged vessels in the wake of the seizure of an Iranian tanker off Gibraltar.
But though this incident has a specifically bilateral dimension, it is also a powerful reminder that the tensions in the Gulf have not gone away.
And with every sign that the dispute over the nuclear agreement with Iran is set to continue, things may only get worse.
The episode may add some impetus to US-brokered efforts to muster an international naval force in the Gulf to protect international shipping.
But most worrying of all, it shows that elements within the Iranian system – the Revolutionary Guard Corps’s naval arm, or whatever – are intent on stoking the pressure.
This inevitably plays into President Trump’s hands as Britain and its key European partners struggle to keep the nuclear agreement alive.
Source: BBC News