A group purporting to be part of Al Qaeda that claimed responsibility for the Madrid train bombings and warned of a looming attack on the United States seems to be a phantom organization, according to US intelligence officials and terrorism specialists.
In a 24-hour news cycle dominated by fears of terrorism, the latest e-mail from the Abu Hafs al Masri Brigade to a London-based Arabic newspaper sowed anxiety and drew instant headlines all over the world.
But specialists say there is no evidence the organization exists. E-mail messages purporting to be written by the group previously claimed responsibility for everything from the North American blackout to a suicide attack that killed 20 Italian policemen in Iraq. But none of those claims has proved true, intelligence specialists say.
The latest message warned that an attack against the United States is "90 percent ready."
Employees at the Al-Quds Al-Arabi newspaper in London, which has received several letters in recent months purporting to be from the group, say they are not sure what the group is.
Deciphering the group -- which first surfaced in July 2003 -- illustrates a larger challenge for counterterrorism officials: assessing the murky world of purported Al Qaeda splinter groups that have been responsible for a dramatic increase in highly sophisticated terrorist bombings around the world.
Spanish officials said yesterday they had no concrete evidence of Al Qaeda involvement in the Thursday attacks, and continued to identify ETA -- a Basque separatist group -- as one suspect.
But the worldwide attention generated by the Abu Hafs al Masri e-mail, received hours after the attacks occurred, demonstrated how easily threats purported to be from Al Qaeda can be spread. Terrorism analysts say such claims form part of the tactics of psychological warfare and propaganda, designed to capitalize on actual violence and deepen public fear of more attacks.
"It goes to the more virtual nature of Al Qaeda," said Peter Bergen, a terrorism specialist at the New America Foundation in Washington. "Some are real; some are waging psychological warfare."