Five armed Iranian Islamic Revolutionary Guard Corps boats attempted to seize a British oil tanker in the Persian Gulf at night, according to the media reports.
CNN cited two U.S. officials as saying that the British Heritage tanker was sailing out of the Persian Gulf and was crossing into the Strait of Hormuz area when it was approached by the Revolutionary Guard boats.
The officials said the Iranians ordered the tanker to change course and stop in Iranian territorial waters.
The U.K.'s Royal Navy frigate HMS Montrose, which was escorting the tanker, is equipped with 30mm guns specifically designed to drive off small boats.
The officials said its crew trained the deck guns on the Iranians and gave them a verbal warning to back away, which they subsequently did.
A U.S. aircraft flying overhead recorded the incident.
A Downing Street 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.”
According to the British government, the U.K. warship stationed in the Gulf was “forced to position herself between the Iranian vessels and British Heritage and issue verbal warnings to the Iranian vessels, which then turned away."
"We are concerned by this action and continue to urge the Iranian authorities to de-escalate the situation in the region," the spokesman added.
Iran’s Revolution Guards denied the U.K. account. "Over the last 24 hours there have been no encounters with foreign vessels, including British vessels," the Tasnim news agency cited the statement as saying.
"In the event that a command is received for the seizure of foreign vessels, the IRGC Navy’s fifth naval zone, in its geographical area of mission, is able to do so immediately, firmly, and promptly," the statement reads.
Britain’s claim that Iran tried to stop one of their oil tankers in the Gulf on Wednesday is worthless, Iran’s Foreign Minister Mohammad Javad Zarif said
The incident follows a warning by Iranian President Hassan Rouhani that the U.K. will face “repercussions” for seizing an Iranian oil tanker last week off the coast of Gibraltar. “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," Fars cited Zarif as saying.
Following the incident, Russian Deputy Foreign Minister Sergey Ryabkov called on the sides to ease tensions.
The British government said the tanker was believed to be carrying 2 million barrels of crude oil to Syria in breach of European Union sanctions against the Bashar al-Assad regime.
Iran denounced the tanker’s seizure as "piracy" and summoned the British envoy in Tehran to protest the action, denying that the tanker was bound for Syria.
On July 9, Tehran vowed to respond to the seizure of the tanker "at an appropriate time and place."
This May and June, six oil tankers were attacked near Iran's southern coast, in incidents the U.S. blamed on Iran. Tehran denied any involvement.
The chairman of the U.S. Joint Chiefs of Staff said it wants to create an international military coalition to secure passage around the Persian Gulf and Yemen.
