Did Madrid Bombs Encourage al Qaeda?

July 8, 2005 — -- Counterterrorism officials learned six weeks ago that al Qaeda has been looking at attacks on rail facilities in Europe and the United States after of the success of the 2004 Madrid bombings, a senior government official told ABC News.

The figure, an al Qaeda operative or person with knowledge of al Qaeda plans, did not provide information specific enough to prevent Thursday's attacks in London, the official said. But the information seemed to match other information from counterterrorism officials.

The March 11, 2004, Madrid attack involved a series of coordinated bombings -- similar to what is believed to have happened in London on Thursday. Nearly 200 people were killed in Madrid.

There has been no definitive evidence that the London attacks were the work of al Qaeda, but British Prime Minister Tony Blair has said they have the "hallmarks" of such an operation.

According to the senior government official, the source also said al Qaeda was also showing interest in derailing trains, launching bomb and vehicle attacks, and possibly attacking aviation.

ABC News' Pierre Thomas reported this story.