MADRID -- Ten bombs in the space of 15 minutes ripped through packed commuter trains and crowded stations during morning rush hour yesterday, killing more than 190 people and wounding at least 1,200 in the worst terrorist attack in Europe since the bombing of a Pan Am flight over Lockerbie, Scotland.
Spanish authorities quickly blamed a Basque separatist group that has waged a 30-year campaign of terror in Spain and that recently vowed to attack train stations to disrupt Sunday's national election. But Spain's Interior Ministry said last night that police had found a stolen van in Alcala de Henares, outside Madrid, with seven detonators and an Arab-language audiotape of Koranic verses near where the bombed trains originated.
Interior Minister Angel Acebes said that while the separatist group, ETA, remained the most likely suspect, there were "other lines of investigation" and officials "would not rule out the possibility of Arab involvement."
The London-based Arabic newspaper Al-Quds al-Arabi said it received an email claiming responsibility in the name of Al Qaeda. The claim was signed by the Brigade of Abu Hafs al-Masri, which has on at least two past occasions issued claims of responsibility later deemed unreliable.
Yesterday's message stated that a "death squad" had penetrated "one of the pillars of the crusade alliance, Spain."
"This is part of settling old accounts with Spain, the crusader, and America's ally in its war against Islam," the message said. Despite massive popular opposition to the war in Iraq, Spain's right-of-center government supported last year's US-led invasion.
The email also stated: "We bring the good news to Muslims of the world that the expected `Winds of Black Death' strike against America is now in its final stage."
The claim could not be immediately verified. One US intelligence official last night said he was skeptical.
"These are the guys that claim responsibility for everything," said the CIA official in Washington, who spoke on condition of anonymity. "They have issued similar statements in the past. They do not speak for Al Qaeda and I would look upon what they say with a critical eye."
In a taped message released in October, a speaker said to be Osama bin Laden declared that Al Qaeda would target any country that supported the US-led war and the occupation of Iraq, specifically mentioning Spain.
More than a dozen Al Qaeda-linked suspects have been captured in Spain since the Sept. 11, 2001, attacks and investigators have revealed that Mohamed Atta, one of the pilots and purported organizers of those hijackings, came to Spain for a meeting with associates the summer before the planes struck the World Trade Center and the Pentagon.
The Batasuna party, ETA's banned political wing, denied responsibility for yesterday's attacks. After an emergency Cabinet meeting, a somber Prime Minister Jose Maria Aznar vowed to hunt down the attackers.
"This is mass murder," he said, declaring three days of national mourning and a halt to all campaigning in the national elections, which will not be postponed.
The blasts began at approximately 7:40 a.m. and detonated in sequence over a 15-minute span along nine miles of the commuter line -- running from Santa Eugenia to Madrid's elegant Atocha central rail station.
Acebes said the 10 bombs were nearly all believed to have been contained in backpacks. Police found and detonated three other bombs.
The explosives tore through the commuter trains and platforms on the commuter line running to Atocha station. Thousands of panicked commuters ran for their lives, abandoning bags and shoes and trampling one another to flee the train terminal, where two bombs exploded.
Rescue workers carried away the bodies of the dead, some of them with their cellphones ringing unanswered, presumably calls from frantic relatives. Hundreds of wounded, faces bloodied, limped and collapsed on the streets. Others sat stunned on curbs as buses were pressed into service as ambulances.
The early trains carried Madrid's working-class commuters from suburbs to jobs at hotels, restaurants, and construction sites. Among them were bricklayers, secretaries, and repairmen; many were immigrants from Latin America and the Philippines.
The attacks were immediately condemned by world leaders, including President Bush and the United Nations Security Council, which also denounced ETA.
Nine area hospitals were flooded with casualties and families and friends desperately searching for loved ones. At the Gregorio Maranon Hospital, medical staff and volunteers held computer printouts listing names of the wounded and dead and told families where to go.
Some were directed to other hospitals, others to a waiting room, and still others to an auditorium where they waited to see whether their loved ones could be located.
The family of Monica Carmen Martinez, 32, a secretary at city hall and mother of a baby girl, was sent to the auditorium. They waited in anguish, politely declining the sandwiches and juice that volunteers offered to the families. Her husband, Jose, dashed off to check another hospital, but word soon came that she was not there, either.
Her father, Juan Manuel Gonzalez, said he heard about the blast on the radio and knew that one of the bombed trains had originated from the station where his daughter boarded a commuter train at that time every morning.
Gonzalez lives near Atocha and ran to the scene, pushing his way past the emergency workers and police who had not yet cordoned off the site.
"I couldn't find her anywhere. I was yelling her name," he said. "There were bags and clothes and bodies and a baby carriage. And there was blood everywhere."
"We know she was on the train. I guess we are waiting for a miracle," he added, his arm around his wife, comforting her. "Anyone who would do this is so evil, so inhuman that it doesn't really matter why they did it or what group they are from."
Relatives at the hospital who wept uncontrollably were mostly those who were instructed to board a bus for the massive makeshift morgue that had been set up at a convention center on the outskirts of the city.
Scores of bodies were so badly mutilated in the attack that authorities said they would have to be identified through DNA and dental records.
Outside the Ifema convention center, relatives and friends of Rex Ferrer, a 20-year-old Filipino immigrant and restaurant worker, waited while his parents went inside to identify his body.
"We are 99 percent sure he is dead, but his parents have gone inside to confirm," said Ronald Quilala, 38, a family friend.
His parents, Arthur and Anita, emerged with their eyes red with tears. The family and friends surrounded them and did their best to comfort them.
The luckier families waited in the lobby of the hospital to see their loved ones who had been wounded. The very lucky families took people home.
Franciso Javier Cordoba, 31, suffered facial cuts from shattered glass, an eye injury, and a broken arm. He was one of the fortunate ones.
"I don't remember anything," said Cordoba, a construction worker who was riding in one of the trains; he said he tripped over the bodies of other victims as he made his way out. "The train was crowded. There were two huge explosions."
"There were so many dead," he added, breaking into tears, as his wife comforted him and then helped get him into the family car to take him home.
Bryan Bender of the Globe staff contributed from Washington. Material from the Associated Press was used in this report.