The British Royal Navy brought guns to bear against a group of Iranian naval boats in the Strait of Hormuz this week as the boats reportedly tried to seize a British oil tanker, according to Sky News.
The tanker British Heritage was approaching the northern entrance to the Strait of Hormuz when several Iranian boats tried to intercept it. A distress call was made and the Royal Navy warship HMS Montrose was sent to lend assistance.
According to the UK’s Ministry of Defence, 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”
In a statement, the UK government said it was "concerned" by the incident and urged Iranian authorities "to de-escalate the situation in the region".
A 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.”
Initial reports from US officials suggested that five Iranian vessels were involved in the incident, and that the British warship was forced to point her guns at the boats before they dispersed.
Iran's Revolutionary Guard has denied claims of a confrontation, saying that if it had received orders to seize any ships it would have executed them immediately.
“There were no clashes with alien boats, especially English boats”, it said in a statement.
The Royal Navy is currently offering extra protection to British vessels in the Arabian Gulf following a threat from Iran to seize a British vessel in response for the impounding of one of its tanker in Gibraltar.
Royal Marines helped seize the Iranian-flagged tanker, which was allegedly carrying oil to Syria, in breach of European Union sanctions.
The capture of the Grace 1 tanker prompted Iranian President Hassan Rouhani to warn the UK of "consequences", while Brigadier General Amir Hatami also warned the UK its actions "will not go without a response".
Tehran claimed the detention was an "illegal interception" and have demanded the tanker's release.
But Gibraltar officials believe the 330m (1,000ft) tanker could have been carrying up to two million barrels of oil destined for Syria.
Iran has denied this and said the boat was headed "somewhere else".Gibraltar's supreme court ruled last week the tanker could be held for another 14 days, the territory's attorney general said.