BBC News Online: World: Middle East

Yemen attack highly 'sophisticated'

US and Yemeni investigators at the scene of the bombing have already found valuable evidence, according to Richard Clarke, the National Security Council co-ordinator for security, speaking on CBS's 60 Minutes programme.

US officials on Friday said they were looking at a number of militant groups in relation to the attack on the USS Cole in the harbour port of Aden.

Saudi-exile Osama Bin Laden's group al-Qa'ida, or "The Base", topped the list, they said.

The United States holds Osama Bin Laden responsible for the 1998 bombings of US embassies in Kenya and Tanzania.

He is on the Federal Bureau of Investigation's list of the 10 most wanted suspected criminals.

Well-planned

US officials believe it was a long-planned and well-financed mission in which two men cruised up to the guided-missile destroyer in a small boat packed with explosives.

The blast killed 17 sailors and injured 39 others.

"It was a very large explosion and did very extensive damage and shows a great deal of sophistication with explosives," Mr Clarke said.

"There are some similarities that we see with East Africa."

"There are similarities in the sophistication of the attack, the pre-planning of the attack," he said.

"This is something that began long before the recent violence in the Middle East."

"This took months to plan and there are indications of safe houses, and planning, and moving of personnel in."