An unidentified Muslim (search) militant suspected of helping plan the Sept. 11 attacks in the United States also ordered this year's Madrid train bombings, a Spanish newspaper said Sunday, asserting the closest link yet between the two terrorist attacks.

The man is believed to be a lieutenant of Mustafa Setmariam (search), a fugitive with dual Syrian and Spanish nationality who is considered a key figure in the March 11 backpack bombings that targeted the Madrid commuter rail network, the newspaper ABC said, citing information from the FBI.

Last week, the United States announced a $5 million reward for information leading to Setmariam's arrest, saying he was an Al Qaeda operative who ran a terrorist training camp in Afghanistan.

Also known as Abu Musab al-Suri, he trained terrorists in poisons and chemicals, the State Department said.

The Madrid attack killed 191 people and was claimed in videotapes by militants saying they acted on behalf of Al Qaeda in revenge for Spain's sending troops to Iraq and Afghanistan. Conservatives who backed the war in Iraq were voted out of power in elections three days after the attack.

The FBI has told Spanish investigators that a man who attended a July 2001 meeting with the Mohamed Atta (search), ringleader of the Sept. 11 hijackers, and suspected coordinator Ramzi Binalshibh in Tarragona, Spain, also came to Madrid last December and activated a cell that staged the train bombings, ABC said.

The identity of the third person at the meeting with Atta and Binalshibh is not known but has been narrowed to three candidates, the paper said.

The new information on that meeting came from US interrogations of Binalshibh, who was arrested in Pakistan in 2002, the newspaper said.

Interior Ministry officials were not available to comment on the report.

Spain's leading anti-terrorism judge, Baltasar Garzon, said in an indictment handed down in September 2003 against 35 al-Qaida suspects — including Osama bin Laden and Setmariam — that the Tarragona meeting was used to decide last-minute details of the attacks on the World Trade Center and the Pentagon, including the exact date.

Investigators in Spain and the United States have long said Spain was a key staging ground for Sept. 11, along with Germany.

In previously established links between the Sept. 11 and Madrid attacks, Spanish officials say Jamal Zougam, one of the 16 people jailed in the investigation of the latter, was a follower of Imad Yarkas, the suspected leader of a Spain-based al-Qaida cell that allegedly provided logistic support and financing to Sept. 11 plotters.

Another alleged follower of Yarkas was Serhane Ben Abdelmajid, a Tunisian described as the Madrid cell's ideologue. He was among seven suspects who blew themselves up on April 3 as police tried to arrest them.

Yarkas has been in jail since November 2001 and was among the 35 suspects indicted by Garzon. The judge later indicted five more, and those in Spanish custody are expected to go on trial next year.