At least six American sailors have been killed in an explosion on a US Navy destroyer in the Yemeni port of Aden. Eleven others are missing and 36 were wounded in the blast. The explosion took place as the crew were refuelling the vessel, the USS Cole, which has been left badly gashed in one side.
American investigators are on their way to the scene.
I have ordered our ships in the region to pull out of port and our land forces to increase their security. Mr Clinton vowed that events would not force a change in US policy in the Middle East. But he added that US forces in the region had stepped up security measures. A BBC correspondent in Cairo says American embassies in the region have already been the focus of angry demonstrations by crowds who believe Washington is siding unfairly with Israel in its conflict with the Palestinians. No-one has claimed responsibility, however.