SANAA - Yemen admitted for the first time that a "terrorist act" was behind the Oct 6 explosion on a French supertanker, which was chartered by national oil company Petronas.

"The (inquiry) results, the evidence and the indications show that a premeditated act of terrorism with a small boat loaded with explosives was the cause," Interior Minister Rashad al-Alimi said, cited by the official Saba news agency.

French and US investigators already said last week the blast on the Limburg off the Yemeni coast, where a Bulgarian sailor was killed, was due to an attack.

"Security services have arrested several suspect individuals to question them ... and the investigation will continue to collect information concerning this act of terrorism," Alimi said.

The minister said Yemeni authorities arrived at the conclusion after a series of "inquiries and investigations conducted (by Sanaa) in cooperation with the teams of American and French investigators."

Tarnished security image

Yemeni security services have identified a "house suspected of having been used to build the (small) boat" located of the port city of Al-Mukalla, capital of the Hadramaut province, Alimi said.

"Traces of explosives were found in the samples (of debris found) aboard the tanker," he added, vowing that the investigation would continue until authorities had arrested "all those implicated in this act of terrorism and those who ordered it."

Already struggling to improve an increasingly tarnished security image, Yemen had initially roundly denied the explosion was terrorism, despite the conclusions of the US and French teams to the contrary.

Alimi said the Limburg attack had "undermined the reputation of Yemen and its economic interests and provoked a (oil) pollution catastrophe which is threatening the marine environment."

US and French investigators had said they found pieces of a fiberglass boat believed to have been used in the attack and traces of TNT. But the Yemenis then insisted they wanted to analyze the evidence for themselves.

Body washed ashore

The tanker's captain and some of its crew said they saw a small boat racing toward their ship seconds before the explosion.

No human remains have been found by divers at the scene of the blast. The body of the Bulgarian, who reportedly drowned after jumping into the waters, later washed up ashore.

Yemeni Prime Minister Abdel Kader Bajamal was to update French officials on the probe during a visit to Paris Wednesday.

His trip coincided with the publication of a statement on an Arabic website that claimed to be from the al-Qaeda network which said: "The operation against this tanker is a message for France."

French Defense Minister Michele Alliot-Marie said that information given so far strongly suggested that the tanker had been targeted by a small boat laden with explosives, in the same manner as the deadly attack against the US destroyer Cole in the Yemeni port of Aden almost exactly two years ago, on Oct 12, 2000.

Extremist militants

The Aden-Abyan Islamic Army, made up of a handful of extremist militants including veterans from the Afghan war against the former Soviet Union, has claimed responsibility for the new blast.

The group - which is not known to have direct ties with al-Qaeda - said its actual target was a US Navy frigate. But it said hitting the Limburg was not a failure, since the supertanker was "going to supply the (US) Fifth Fleet for striking the brothers in Iraq."

Yemeni authorities also said that security had been increased around all their ports.