An explosion from a suspected attack hit a Japanese tanker yesterday in the Strait of Hormuz near Iran, officials said, spotlighting a potential threat in a chokepoint for global oil supplies.

One crew member was injured and the ship, the M. Star of the Mitsui OSK Lines, was partly damaged but able to keep sailing after the blast, Japan’s Transport Ministry said.

“Since one of the crew saw a flash on the horizon immediately before the blast, the company suspects it was highly likely an attack,” the ministry said, adding that the immediate area was not known for commercial piracy.

The vessel – staffed by 16 crew from the Philippines and 15 Indians – was carrying 270,000 tonnes of crude oil but did not suffer a spill.

The tanker was heading from the United Arab Emirates toward the Japanese port of Chiba, east of Tokyo, at the time of the blast, but then turned back for inspection in a port in the UAE, a company official said.

The Strait of Hormuz links the Gulf – including the ports of oil-rich states such as Kuwait, Bahrain and Qatar – with the Arabian Sea and Indian Ocean, making it a strategic conduit for global energy supplies.

Bahrain, across the Gulf from Iran, is the base for the US Fifth Fleet and the main host for American forces in the Gulf.

The cause of the explosion was “maybe an attack, not a spontaneous accident, it may be a terrorist attack”, Junto Endoh, general manager in the Doha liaison office for Mitsui OSK Lines, told Dow Jones Newswires.

“The vessel is now navigating towards Fujairah by itself,” he said, referring to one of the seven emirates that make up the UAE, adding that the explosion had not been “huge”.

Eiko Mizuno, a Mitsui spokesman in Tokyo, said: “The crew member was not seriously injured. His arm was cut by shattered glass.