Taking a tough stance against Iran, the UK has increased its naval presence in the troubled Gulf waters following an attempt by three vessels of the Revolutionary Guards to intercept a British oil tanker.

According to the Guardian, a Royal Navy warship had trained its guns on Iranian gunboats that had tried to disrupt the passage of an Isle of Man-flagged vessel.

Reports said that British Heritage, a commercial ship, was in the disputed waters when it was challenged by three Iranian vessels and ordered to move north. The Ministry of Defence said the Iranians ordered the vessel to stop in nearby Iranian territorial waters. However, HMS Montrose, a Royal Navy frigate intervened and the Iranian boats backed off.

“Contrary to international law, three Iranian vessels attempted to impede the passage of a commercial vessel, British Heritage, through the Strait of Hormuz,” a Ministry of Defence spokesman 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,” he said.

This comes after the British government placed a level 3 alert last Tuesday. Experts describe level 3 alert being equivalent to domestic security classification of critical, with imminent risk of incidents. British Foreign Secretary, Jeremy Hunt, said Britain could help secure the release of a supertanker that was seized in Gibraltar if Iran provided sufficient guarantees that the cargo was not bound for Syria. Hunt described a call with Iranian counterpart, Javad Zarif about the Grace 1 tanker as constructive.

The British and Gibraltan authorities suspect the ship of violating EU sanctions by transporting oil to Syria. 

Meanwhile, the US President Donald Trump has applauded the action by UK. “It seems that the Brits and the French and the Germans are coming around the idea that the Iranians are up to no good,” he had tweeted on Thursday.