Europe's spies worried by terror alert

BERLIN, Oct. 12 (UPI) -- European intelligence agencies are increasingly concerned that terrorists might carry out attacks on the continent.

For the past eight days, terror-related travel alerts issued by the United States, Britain and Japan have kept European intelligence officials at the edge of their seats. A day after the alert was issued, a U.S. drone killed what officials said were several militants, some of them German nationals, at a hideout in Pakistan.

Media reports suggested that the travel alerts were based on intelligence gathered from Ahmed Sidiqi, a German of Afghan descent in custody of U.S. forces in Afghanistan. The man from Hamburg had told U.S. interrogators about Mumbai-style attack plans in Europe.

German security officials played down the warnings.

"There is no concrete evidence for imminent attacks in Germany," German Interior Minister Thomas de Maiziere said last week.

Yet behind the scenes, the Germans are more concerned than they are admitting, a European security official told CNN.

"The threat is being taken very seriously -- an attempt at an attack is considered likely," the official, who didn't want to be named, told CNN.

Sidiqi left Hamburg in 2009 as part of a larger group of German-born militants eager to receive weapons training in the border region between Pakistan and Afghanistan.

He was captured by U.S. forces this summer and has since been interrogated by U.S. -- and reportedly German -- intelligence officers in Afghanistan.

An unnamed Hamburg intelligence official told Time magazine that authorities knew Sidiqi was a committed jihadist.

"But we assumed that when he and the others left Germany in 2009, they would stay and fight against international forces in Afghanistan and weren't planning to carry out attacks in Europe," the officer said.

Individual members of Sidiqi's travel group have reportedly been killed in the drone strike; others are back in Germany or still at large.

The German police union puts the number of violent extremists in Germany ready to commit attacks at 40. The union's head said last week the police aren't sufficiently staffed to constantly monitor all of them.

Sidiqi told U.S. interrogators that terrorist sleeper cells are planning commando-style attacks in Germany and France. German news magazine Der Spiegel reports that Sidiqi told U.S. interrogators he met with high-level al-Qaida members who told him about the plans.

Media reports suggested the plots mimic the coordinated attacks by gunmen on several targets in Mumbai in late 2008. The militants stormed several public and private buildings, including the Taj Mahal Palace hotel and killed 165 people.