More than 186 people were killed and some 1,000 injured in a series of rush hour bomb blasts which ripped through three Madrid railway stations in the worst ever terror attack on Spanish soil. World leaders condemned the coordinated blasts as an attack on democracy coming just three days before Sunday's generals elections, and urged a joint stand to fight against terrorism. Interior Minister Angel Acebes said 13 bombs had been placed in stations and trains around Madrid, of which 10 had gone off within minutes of each other, adding there was "no doubt" the separatist Basque group ETA, which is on the US list of banned terror organisations, was behind the attack. But the leader of the banned Basque Batasuna political party denied the charge and condemned the attacks, which judicial sources at the scene said killed more than 186 people and injured more than 1,000. Instead Batasuna party leader Arnaldo Otegi highlighted Spain's role in the US-led occupation of Iraq which has already drawn warnings of revenge attacks from "Arab resistance". "ETA has always issued a warning whenever it left a bomb to explode" he said, recalling that "Spain maintains occupation forces in Iraq and we should not forget that it had a responsibility for the war in Iraq." Commuters faced scenes of carnage with bodies strewn across tracks and in the wreckage of the four trains targetted by the blasts at the Atocha station in central Madrid, as well as the suburban Santa Eugenia and Pozo stations. Three more bombs were detonated in controlled explosions by the Spanish authorities, Acebes said. He gave an earlier toll of more than 173 dead and 600 wounded. Spanish Prime Minister Jose Maria Aznar, who himself escaped an ETA attempt on his life in 1995, just months before he became premier, vowed to hunt down those responsible for the blasts. "We will not back down in the face of terrorist killings. The perpetrators will be tried and convicted," he said in a national address, without referring directly to ETA. "There can be no negotiation with these murderers. We will only stop these attacks by taking a hard line," he added. Acebes insisted the attacks had been carried out by the armed group which has led a 36-year campaign for a separatist Basque homeland in which over 800 people have died on both sides. "ETA were looking to carry out a massacre" in Madrid "and they have achieved their objective," Acebes said. Spanish anti-terrorist sources said all 13 bombs were made of dynamite, of a type habitually used by ETA. The blasts occurred within minutes of each other starting from 7:30 am (0630 GMT) as morning commuters arrived at the three stations. Rescue services and hospitals appealed for blood donations to cope with the flood of injured as horrified onlookers watched scenes of carnage unfolding before their eyes. **PHOTO CAPTION*** Rescue workers cover up bodies alongside a bomb-damaged passenger train, following a number of explosions in Madrid, Spain, March 11, 2004, just three days before Spain's general elections. (AP Photo/Paul White)