BAGHDAD, April 8: Despite earlier indicating that up to 40 guerillas were killed in Wednesday's air strike on a mosque in Fallujah, a marine officer has admitted that soldiers had failed to find any bodies inside.

"When we hit that building I thought we had killed all the bad guys, but when we went in they didn't find any bad guys in the building," Lt Col Brennan Byrne said. Instead, he speculated the guerillas may have fled after a Cobra helicopter gunship fired a Hellfire missile at the mosque, and before an aircraft dropped a laser-guided precision bomb.

Marines moved cautiously through Fallujah's neighbourhoods on Thursday as they sought to round up those responsible for the recent deaths and mutilation of four security contractors.