A Spanish newspaper says U.S. investigators have found the clearest link yet between the September 11, 2001 terrorist attacks and the Madrid train bombings earlier this year.

The ABC newspaper says the FBI has told Spanish investigators that one of the men who helped plan the September 11 attacks also gave the order to carry out the Madrid blasts.

The Madrid-based daily says investigators do not know the man's identity but believe that during the summer of 2001 he met in Spain with Mohammad Atta, one of the lead September 11 hijackers.

It says investigators believe the man is a lieutenant of Mustafa Setmarian, a leading al-Qaida operative.  The U.S. State Department recently offered 5 million dollars for information leading to Mr. Setmarian's capture.

Al-Qaida has claimed responsibility for both the Madrid bombings, which killed 191 people, and the September 11 attacks, which killed some 3,000.

Some information for this report provided by Reuters.