The Norwegian tanker Front Altair was "attacked" Thursday in the Gulf of Oman, with three explosions but no injuries reported on board, the Norwegian Maritime Authority said.

 

Another reported attack in the same zone targeted the vessel Kokuka Courageous, the authority said in a statement.

 

The Front Altair, a 111,000-tonne oil tanker, is currently ablaze and emergency crews are at the scene, it added.

 

"Today, June 13 at 6:03 am, the Front Altair, a Marshall Islands-flagged vessel, was attacked between the Emirates and Iran," the statement said.

 

"Three explosions on board the vessel were reported. The crew boarded a passing vessel and no injuries have been reported."

 

Meanwhile, the US 5th Fleet, based in the region, said it had received two "distress signals" from tankers in the Gulf of Oman which had been targeted in an "attack".

 

The Iranian news agency Irna said Tehran had come to the aid of "two foreign tankers" that had had an "accident", citing an "informed source".

 

Thursday's incident comes one month after a series of presumed mysterious "acts of sabotage" targeted four commercial vessels, including a Norwegian tanker.

 

Saudi Arabia had attributed those acts to Iran.

 

Norwegian authorities called on its ships in the region to exercise extra caution.

 

"Even if the background for these attacks is not totally clear, the Norwegian Maritime Authority recommends, after today's episode, to stay well clear of Iranian waters until further notice," it said.