The 10 chief suspects in the bombing of the USS Cole have escaped from custody in Aden, local officials said.
The repaired Cole has gone back into service since the attack
Security forces mounted a major search operation in the Yemeni port where the 10 had been held since shortly after the attack in October 2000.
Chief suspect Jamal al-Badawi is among the escapees who reportedly got out through a prison window early on Friday.
Seventeen US sailors died and 37 were wounded when two suicide attackers in a bomb-laden dinghy rammed their destroyer in the port in an attack widely blamed on al-Qaeda.
Mr al-Badawi allegedly helped buy the dinghy.
The men broke out of a window around 0500 (0200 GMT) and their absence was not discovered by warders for another hour, local officials told AFP news agency on condition of anonymity.
Photographs of the escapees have been distributed to police and intelligence agents, the Saudi news agency SPA reports, and houses of the escaped men's relatives have been searched.
Yemeni officials said the men may have left Aden and headed for al-Qaeda strongholds in the northern province of Shabwah.