U.S. law enforcement officials have released videotaped excerpts of five suspected al-Qaida terrorists who may be planning suicide missions.

Attorney General John Ashcroft says the video excerpts were taken from five videotapes recovered by U.S. soldiers in Afghanistan. The tapes were found in the rubble of the home of Mohammed Atef, one of Osama bin Laden's top aides, whom U.S. officials believe was killed by an air strike in November.

Mr. Ashcroft played the video excerpts at a Washington news conference Thursday and says the video clips will be circulated worldwide. The excerpts consist of a series of close-up shots of the five men, four of whom have been identified by U.S. intelligence analysts.

Officials did not play the audio sound track that accompanied the video, but Attorney General Ashcroft says an initial analysis of the audio track indicates that the five men could be planning suicide terrorist attacks. "We believe that these could be, likely appear to be, sort of martyrdom messages from suicide terrorists," he said. "And whether or not the attack would be imminent or not is something that we can't determine. But we know that the right time to release these is in advance of any attack, if there is to be an attack, not subsequent to an attack."

Mr. Ashcroft says there is no indication that any of the five men have tried to enter the United States, adding that they could be anywhere in the world.

The attorney general and FBI Director Robert Mueller also renewed their appeal to the public both in the United States and abroad to remain vigilant in the war on terrorism and to contact law enforcement officials if they recognize any of the five men depicted in the videotape.

U.S. officials say that documents and a videotape found in Afghanistan previously helped authorities in Singapore foil a suspected terrorist attack by al-Qaida operatives there.