By Adrian Croft
Madrid - Spanish voters swept the centre-right government from power on Sunday in a spectacular general election upset over last week's suspected al-Qaeda attack in Madrid.
The ruling Popular Party (PP) conceded defeat to Socialist leader Jose Luis Rodriguez Zapatero, who will take over from outgoing Prime Minister Jose Maria Aznar, a staunch supporter of the United States-led war in Iraq that most Spaniards opposed.
"My most immediate priority is to beat all forms of terrorism," said Zapatero, asking for a minute's silence in honour of the 200 people killed in the bombings on four packed commuter trains.
Voters, many wearing the black ribbon symbols of national grief since Thursday's attack, turned out in large numbers amid an angry debate over who was behind the train bombings - Osama bin Laden's al-Qaeda or Basque separatists.
Analysts had warned that the PP, which had been opinion poll favourite, could be hit if voters believed a purported fresh al-Qaeda claim that the group had mounted its first attack in Europe and in reprisal for Spain's support for the Iraq war.
"The government has paid the price for its involvement in the war in Iraq, for Aznar's relationship with (US President George) Bush and (British Prime Minister) Tony Blair. The vote has been a reaction to this," said Carlos Berzosa, rector of Madrid's Complutense University.
Official results showed the Socialists leading the PP by 42.7 percent to 37.7 percent with 96 percent of votes counted.
This would give the Socialists 164 seats in parliament compared with the PP's 148, but short of an absolute majority of 176.
Some Spaniards were vitriolic in accusing Aznar of "manipulating" public opinion by spending three days blaming the bombings on the Basque separatist group ETA, despite its denials.
Aznar, retiring as prime minister and hailing a solid economy and greater clout for a country restored to the international mainstream three decades after Franco's dictatorship ended, had taken a tough line against ETA.
Protesters shouted "Liar" and "Get our troops out of Iraq" at the PP's leading candidate Mariano Rajoy when he voted.
The Socialists have pledged to withdraw Spain's 1 300 troops from Iraq if the United Nations does not take control by June 30 when Washington plans to hand power back to Iraqis. Opinion polls showed as many as 90 percent of Spaniards opposed the Iraq war.
In a high turnout, voters said they wanted to display unity for democracy after the worst guerrilla attack in Europe since the 1988 Lockerbie bombing of a US airliner killed 270 people.
Just hours before polling began, officials said a purported al-Qaeda video had been found in a waste bin on the outskirts of Madrid and that three Moroccans and two Indians had been arrested in connection with the attack.
Interior Minister Angel Acebes told a news conference in the early hours a purported spokesperson for al-Qaeda had claimed responsibility for the bombings on the video.
Morocco identified its three detained citizens as Jamal Zougam, 30, an office worker, mechanic Mohamed Bekkali, 31, and Mohamed Chaoui, 34, a factory worker.
On the tape, a man speaking in Moroccan-accented Arabic said al-Qaeda had retaliated for Spain's support for Washington.
"If you don't stop your injustices, more blood will flow and these attacks are very little compared with what may happen with what you call terrorism," he said, according to a transcript in Spanish from the Interior Ministry. The tape was not released.
The man, who said he was speaking for Abu Dujan al Afgani whom he described as military spokesperson of al-Qaeda in Europe, referred to Iraq and Afghanistan where Spain has troops.
The caller noted the March 11 blasts occurred exactly two-and-a-half years after the September 11 attacks on the United States.
A purported al-Qaeda letter on Thursday also claimed the group was responsible for the 10 simultaneous bombings on the crowded trains.
ETA issued a second statement, made public on Sunday, denying any role. The size of the attack would be unprecedented in the group's three-decade armed campaign for independence.
Germany called on Sunday for an urgent meeting of European Union security chiefs as possible al Qaeda involvement in the Madrid bombings triggered alarm bells across the world.
From Paris to Warsaw, governments across Europe tightened security at borders, railways and airports.