London on alert, but threat not 'imminent'

LONDON, Jan. 7 (UPI) -- British authorities called in extra support Friday to monitor rail stations after intelligence agencies warned of possible terrorist activity, sources said.

Train stations in London were placed on high alert Friday after authorities warned of a grave risk to transportation hubs, London's Telegraph newspaper reports.

"The assessment of the threat to transport hubs has been revised," a government source told the newspaper. "The view is that there is a greater risk than before, so steps are being taken as a precaution."

British security sources, nevertheless, told the newspaper there was no "imminent" threat, though a "handful" of suspected terrorists caused authorities to take extra precautions.

Police in Denmark last week arrested three men who were allegedly plotting an attack similar to the assault on Mumbai in 2008.

A suicide bomber set off his device Dec. 11 at a train station in Sweden.

Both cases, the Telegraph notes, had ties to London.

Europe was put on edge last year when information from al-Qaida suspects lent authorities to believe terrorists were planning a similar siege on European targets.

Central authorities in New Delhi in December warned security agents to step up patrols in and around Mumbai.

Gunmen tied to the Pakistani-based Lashkar-e-Toiba staged a 60-hour siege on high-profile targets in Mumbai in November 2008. About 170 people died, including 23 foreigners, and hundreds more were injured.