Supertanker 'was damaged by explosion or submarine'

A JAPANESE supertanker which sustained serious hull damage while sailing through the hyper-sensitive Straits of Hormuz was either hit by an explosion or in a collision with a submarine, officials in the United Arab Emirates said yesterday.

•The damage to the hull of the M Star is clear to see. Below, the tanker in open seas Pictures: AFP

When the M Star supertanker reported it had been hit by an "explosion" late on Wednesday, officials in the UAE played down the claim, citing seismic activity and saying the vessel had been hit by "a freak wave".

Yet yesterday, it was confirmed the crude carrier had been hit by an external force and a specialist on military attacks has been asked to help investigate damage to the 1,100-foot vessel laden with oil for Japan.

"What we know is some collision happened. We don't know what it was," said Captain Mousa Mourad, general manager at the UAE port of Fujairah.

"It's possible that it could be a submarine collision, or that it could be a sea mine."

The Straits of Hormuz are a strategically vital waterway; a narrow chokepoint between Iran and an enclave of Oman surrounded by Emirati territory through which 40 per cent of the world's shipped oil must transit.

Iran has frequently threatened to blockade them in the event of any military action against it, and the US maintains a constant naval presence in the area.

A spokesman for the US Fifth Fleet, based in Bahrain, said no American warships were in the area at the time the M Star reported the incident.

US nuclear submarines have been involved in two collisions in the busy sealane since 2007, one involving a Japanese supertanker and the other another US warship.

A photograph released by the Emirates state news agency WAM after the tanker arrived in Fujairah yesterday showed a large, square-shaped dent near the waterline on the rear starboard side of the ship's hull.

Wednesday's incident happened shortly after midnight as the ship entered the Strait of Hormuz, heading out of the Persian Gulf, Japanese shipping company Mitsui OSK. Lines said.

The incident briefly spooked oil markets particularly in Japan - a sign of the heightened focus on the Gulf after new sanctions were imposed on Iran at the beginning of the week.

"In international waters, it is always difficult to tell what happened," said Jonathan Wood, global issues analyst at Control Risks. "It could be an accident or it could be an attack.

It took weeks to raise the South Korean corvette Cheonan after it sank in March and for Seoul to blame North Korea. Investigating this could be easier - the ship is still afloat.

Attacks on land are hard enough to probe, but at sea independent witnesses may be scarce, radar and satellite coverage patchy and physical evidence at the bottom of the sea.Darkness and bad weather can all play a role - and some crews may try to conceal their own mistakes such as keeping a poor lookout or poorly maintaining equipment.

If the tanker was attacked, it would be a rare assault on a merchant ship in the Persian Gulf or at the Straits of Hormuz. Al-Qaeda has, in the past, carried out attacks on oil infrastructure on land in nearby Saudi Arabia, as well as a 2002 suicide bombing against a French oil tanker off the coast of Yemen and the 2000 bombing of the USS Cole in the Yemeni port of Aden.

One of the tanker's 31 crew members noticed a flash of light right before the explosion, suggesting something may have struck the vessel.

The explosion occurred at the back of the tanker, near an area where rescue boats are stored, causing cuts to a crew member who was struck with broken glass.

The Marshall Islands-flagged tanker, loaded with 270,000 tons of oil, was heading from the petroleum port of Das Island in the United Arab Emirates to the Japanese port of Chiba outside Tokyo.