WASHINGTON //An explosion on a Japanese tanker in July off the coast of Oman was a terrorist attack, according to the US department of transportation, which has urged ships in the area to exercise "increased vigilance".
In August, just days after the incident, the Emirati state news agency, WAM, said that a boat piled with explosives struck the tanker. It was the first official word that the incident was an attack. The news agency, quoting an unnamed government official, said traces of homemade explosives were found on the hull of the tanker, indicating the vessel had been subjected to a terrorist attack.
And, in an advisory issued on Friday, the department's maritime administration agreed, saying it had determined that claims of responsibility for the explosion by the Abdullah Azzam Brigades were valid. The explosion injured one sailor.
The al Qa'eda-affiliated group, according to the advisory, "remains active and can conduct further attacks on vessels in areas in the Strait of Hormuz, southern Arabian Gulf, and western Gulf of Oman".
It is not clear how the department reached its conclusion. A spokeswoman yesterday would only say that the determination had been made based on information "received from various government sources". However, neither the US department of defence nor the State Department would make any comment and referred the matter back to the department of transportation.
Japan's maritime bureau, meanwhile, said it was still conducting an investigation into the events on the M-Star tanker on July 28, and that any conclusions reached by the US had been reached independently of Japan.
"We are not trying to approach the US government about this issue," said Ichio Motono, the director of the security office in the maritime bureau, part of Japan's ministry of land, infrastructure, transport and tourism.
"When our investigation is concluded, if necessary, we will try to contact the US government, the UAE government and the Oman government. But right now the investigation is still in the works, so we haven't decided which information we should provide to other countries."
The company that owns M-Star, Mitsui OSK Lines, deferred to the bureau.
The Abdullah Azzam Brigades claimed responsibility for the incident, saying a suicide bomber had set off the explosion. But the group has a history of taking responsibility for attacks carried out by other groups, and the claim did not at first carry much credibility.
Instead, a number of different theories have been put forward to explain the explosion, which caused no oil spill or disruption to shipping in the waterway, including that the tanker was hit by a freak wave, a mine or had collided with a US nuclear submarine.
According to the Brigades’ August 4 statement, however, the “enemy” could not reveal that the explosion had been an attack since that would have sent oil prices soaring.
That would have been an unlikely outcome, said Charles Ebinger, director of the Energy Security Initiative at the Brookings Institute, a Washington-based think tank, who pointed out that this was not the first incident involving oil tankers.
He suggested, with reference also to the recent explosives discovered on freight planes in the UAE and England, that if the M-Star incident were an attack it would fit into a pattern in which global infrastructure has increasingly become a target for al Qa’eda and al Qaeda-affiliated groups.
“It’s a big problem. This is a low budget way for terrorists to put huge costs on all the countries in the area that rely on transit.”
Nevertheless, the incident was unlikely to significantly affect shipping in the Strait of Hormuz, Mr Ebinger said, even if it would drive up insurance premiums.
The Strait, bordered by the UAE, Iran and Oman, is one of the world’s most important strategic waterways and handles 40 per cent of the world’s oil shipping.
* With additional reporting by Carol Huang