A German security source said there were "increasing rumblings" about potential attacks, but the interior ministry said there was no reason to raise the national alert level.

The comments followed a report by Britain's Sky News that intelligence agencies had disrupted plans by Pakistan-based militants for simultaneous strikes in London, as well as in cities in France and Germany.

Citing unidentified intelligence sources, Sky said the planned attacks would have been similar to the commando-style raids on Mumbai in 2008 in which Pakistan-based gunmen killed 166 people.

Sky said an increase in strikes by unmanned US drone aircraft on suspected militants in Pakistan in the past few weeks was part of Western efforts to thwart the plot, which it said was at an "advanced but not imminent stage."

Pakistan's army dismissed the report as "very speculative."

Military spokesman Major General Athar Abbas told Reuters: "We don't have any information or intelligence that militants had gathered there (in North Waziristan) and were plotting attacks. There is absolutely no intelligence on that."
 
THREAT REMAINS

US security officials said they could not confirm that a plot had been disrupted. But they said they believed that the threat of a plot or plots remained. British security officials declined to comment on the Sky report.

The German interior ministry said in a statement that it knew about the information on possible attacks and that this had been exchanged with other countries with the requisite "sensitivity and intensity."

"At present there are no concrete pointers to imminent attacks in Germany stemming from this. The current pointers do not warrant a change in the assessment of the danger level," it said.

Speaking on condition of anonymity, one security official in Germany said the reports had probably been sparked by the interrogation of a German-Afghan terrorism suspect in Afghanistan.

"We're hearing increasing rumblings, which you have to take very seriously — but no concrete pointers," the official said, when asked about the veracity of the reports.

The suspect believed to be behind the revelations was identified by media as Ahmed Sidiqi, a German of Afghan origin. German media said he came from Hamburg and had been held in the US military prison of Bagram in Afghanistan since July.

Four US security officials, who asked for anonymity, said that initial intelligence reports about the threat first surfaced roughly two weeks ago, around the time of the anniversary of the Sept. 11, 2001, attacks on the United States.

Britain in January raised its international terrorism threat level to "severe" — the second highest level of alert. The head of the MI5 security service said on Sept. 16 there remained "a serious risk of a lethal attack taking place."

French Interior Minister Brice Hortefeux said on Sept. 20 France faced a real terrorism threat due to a backlash from Al-Qaeda militants in North Africa, with fears growing of an attack from home-grown cells within French borders.

The Eiffel Tower and the surrounding Champ de Mars park were briefly evacuated on Tuesday because of a bomb alert, the fourth such alert in the Paris region in as many weeks, but a search turned up nothing, police said.
 
RECORD DRONE STRIKES

US intelligence chief James Clapper said in a statement: "As we have repeatedly said, we know Al-Qaeda wants to attack Europe and the United States. We continue to work closely with our European allies on the threat from international terrorism, including Al-Qaeda."

One US official said militants in Pakistan were "constantly" planning attacks in the region and beyond, and the United States would react to that.

"It shouldn't surprise anyone that links between plots and those who are orchestrating them lead to decisive American action. The terrorists who are involved are, as everyone should expect, going to be targets. That's the whole point of all of this," the official said.

Remotely piloted drones have carried out 21 strikes in September, the highest number in a single month.

On Sept 26, a senior Al-Qaeda leader, identified as Shaikh Al-Fateh, also known as Shaikh Fateh Al-Masri, was believed to have been killed, Pakistani intelligence officials said.

Pakistan's Tehrik-e-Taleban (TTP), or Taleban Movement of Pakistan, has made several threats against American and European targets, but has so far failed to carry out any overseas attacks.