WASHINGTON - Al Qaeda may be planning to attack rail and air travel in Europe - possibly targeting the busy holiday travel season - according to intelligence findings, the "CBS Evening News" reported on Friday.

The report, citing Arab and other intelligence sources, said interrogations of al Qaeda suspects who recently left Afghanistan and Pakistan raised the concerns.

"One suspect said plans for repeating the Heathrow attempt (a plot foiled in August to bomb trans-Atlantic airplanes) were all prepared," the network quoted an Arab official as saying.

"It is now a matter of taking action ... Al Qaeda's strategy appears to be raising the pressure in Europe," the official, who requested anonymity, told the network.

The report came as Britain's intelligence agency, MI5, said on Friday that Muslim extremists were plotting at least 30 major terrorist attacks in Britain, and the threats may involve chemical and nuclear devices.

Britain suffered its worst peacetime attack in July 2005 when four British Islamists blew themselves up on London's transport network, killing 52 commuters and wounding hundreds.