Security in Germany

Following a bomb threat from an anonymous telephone caller, German police and the US military mounted a large-scale security operation at the Spangdahlem Air Base close to Trier, near the border with Luxembourg.

Though police said they believed the call was a hoax, security was increased as a "preventative measure."

Police said there was no "concrete threat" to the public, but that the security operation was a precaution due to the sixth anniversary of the Sept. 11 terrorist attacks in the US.

German police said that the US base at Spangdahlem received the telephone threat late Monday afternoon.

"The man, who spoke in German with an accent that could have

been Turkish or Russian, threatened to attack the Spangdahlem base

with at least four accomplices," a police spokesman told AFP news agency.

There was mention of bombs during the call, police said.

Bomb threat follows last week's foiled attacks

"While we have no additional information to validate a direct attack against Spangdahlem, we take every threat seriously," US military spokeswoman Sergeant Andrea Knudson told AFP.

The US armed forces immediately informed German police of the anonymous call on Monday. German authorities then set up protective measures at the base with the cooperation of the American military.

German police spokesman Reinhard Rothgerber told AP news agency that police were trying to track down the anonymous caller.

The threat came less than a week after German police foiled what they said would have been "massive attacks" on US installations in Germany and possibly the Frankfurt Airport.

There was specualtion that the three Islamists German authorities arrested one week ago were planning attacks to coincide with the Sept. 11th anniversary.

Spangdahlem Air Base is one of the US Air Force's main sites in Europe which operates fighter jets.

US forces are responsible for security within the base, while German police patrol the perimeter.