Updated

Senior Al Qaeda leaders, including Usama Bin Laden, are believed to be behind efforts to mount a Mumbai-style attack on Westerners in European cities, a senior U.S. intelligence official told Fox News, though it's not clear how deeply involved Bin Laden was in the plot.

The news comes on the same day that Bin Laden released an audio recording in which he depicts the Pakistani government as uncaring and calls for the creation of a new relief organization to help Muslims after this summer's devastating floods.

The emerging details of the European plot point to coordinated shooting sprees or attacks and kidnappings in Britain, France and Germany -- tactics much favored by Al Qaeda. The plot was moving forward with dual national citizens, who had Pakistani and European passports, the official told Fox News, adding that Western officials intended to disrupt the plot by publicly exposing it.

Another senior U.S. official told Fox News that there is "some evidence within the intelligence community that Bid Laden was involved in plotting this foiled attack."

This official said it's believed Bin Laden was giving "broader guidance" in this case, citing the suggestion for attackers to go after softer targets in Europe.

This official noted the intelligence community has not made a direct link to Bin Laden in some of the more recent Al Qaeda attacks and plots.

"At a minimum, he played a role," this official said. "But not everyone [in the intelligence community] agrees to the level of his involvement."

Another official said that Bin Laden and his top lieutenants are believed to be driving the plot because the intelligence is coming from Pakistan, where they are believed to be hiding.

"There are multiple plots and multiple threat streams" coming out of the tribal areas of Pakistan right now," the official said, cautioning that all avenues are still being explored.

Because of the U.S.-led crackdown on Al Qaeda and other terror groups, Bin Laden and his allies have changed strategy -- abandoning their earlier preference for big spectacular attacks like the one on the World Trade Center in 2001 in favor of using low-impact technology, as they did two years ago in Mumbai in an attack that devastated India.

One senior U.S. official, meanwhile, discounted any involvement in the Europe terror plot by Al Qaeda's North African affiliate. While Al Qaeda in the Islamic Maghreb is very dangerous in its region and may want to export its terror operations to Europe, there are no indications that it is able to do that at this time, the official said.

A Pakistani intelligence official said Thursday that eight Germans and two British brothers are at the heart of the terror plot, still in its early stages. One of the Britons was killed in a recent CIA missile strike, he said.

Pakistan, Britain and Germany are tracking the suspects and intercepting their phone calls, the official told The Associated Press on condition of anonymity because he was not authorized to release the information to the media.

The U.S. has dramatically stepped up its missile attacks in Pakistan's North Waziristan and is believed to have launched at least 21 this month. The covert campaign is largely carried out by CIA drones and has led to the deaths of a number of top militant leaders.

Pakistan has complained vocally about the program but is believed to provide intelligence assistance for at least some of the strikes.

Fox News' Jennifer Griffin, Catherine Herridge, Justin Fishel and The Associated Press contributed to this report.