CAIRO: Two Indian vessels have had to reverse course in the Strait of Hormuz following reports of gunfire from Iran's Revolutionary Guard, a vessel-tracker said.

TankerTrackers.com said the vessels include an Indian-flagged super tanker, carrying 2 million barrels of Iraqi oil.

Earlier, the British military said two gunboats from Iran's Revolutionary Guard opened fire on a tanker transiting the Strait of Hormuz after Iran said it had reimposed restrictions on the vital waterway.

The United Kingdom Maritime Trade Operations Centre said the tanker and crew were reported safe, without identifying the vessel or its destination.

Iran said earlier it was reimposing restrictions on the strait in response to a US blockade on Iranian shipping and ports. Iran has prevented vessels from crossing throughout the seven-week-long war, except for ones it authorises.