Police said they found a third cache of explosives in Spain's Basque region on Friday, nearly a week after a massive car bomb at Madrid airport's gleaming new terminal killed two people and ended a nine-month cease-fire that separatists had said would be permanent.

Basque police said Friday that they had recovered 130 pounds of explosives inside a backpack, as well as bomb-making manuals, in the valley of Atxondo near the Basque towns of Amorebieta and Durango.

It was in the same area were on Thursday they had found 220 pounds of explosives that they said were ready for immediate use, lacking only a detonator.

Earlier Friday during the search of the area, they also found more bomb-making materials, including 44 pounds of ammonium nitrate, detonators and timers in a small hole underground.

ETA has not claimed responsibility for the blast, but a man who made a warning call to authorities before the explosion said he represented the group.

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The governing Socialist party acknowledged Friday that Saturday's bombing at Madrid's airport betrayed the government's lack of communication with the Basque militant group, despite the cease-fire that had raised hopes of an end to four decades of separatist violence.

"We have to recognize that there was a problem of information and no dialogue," senior Socialist party official Jose Blanco told the radio station Cadena Ser. "We have to analyze what happened to avoid repeating the same mistakes in the future," he added.

Zapatero had announced in June that he believed the truce was sincere and said he would negotiate with ETA — although he ruled out concessions toward Basque independence.

However, those talks never got off the ground.

The government has rejected demands from ETA and its political wing, Batasuna, for preliminary gestures such as moving some ETA prisoners to the Basque region and allowing separate talks among Basque political parties on the region's future. ETA also has criticized the government for refusing to let up on the movement, citing the continued arrests of suspected ETA members.

ETA's fight for an independent Basque state has killed more than 800 people since the 1960s, but Saturday's blast was the Basque separatist group's first fatal attack in more than three years. The last was a May 2003 car bombing that killed two policemen in the northern town of Sanguesa.

Until the truce, ETA had kept up relatively low-scale attacks on such targets as empty buildings.

Earlier Friday, firefighters spotted remains believed to be those of Diego Armando Estacio, 19, a second man missing since the Madrid airport bombing.

Estacio, from Ecuador, was believed to have been sleeping in a car in the multistory parking garage. Due to the precarious location of the body, where tons of rubble endangered rescue workers, Estacio's body was unlikely to be recovered before Saturday.

Another Ecuadorean, Carlos Alonso Palate, 35, who was at the airport separately and also sleeping in a parked car, was found Wednesday in the debris. His body was sent to his hometown in Ecuador on Thursday.

Zapatero warned ETA that the government and the people of Spain would not be intimidated by the bombing.

"It will achieve nothing. It is not going to intimidate anyone," he said Thursday after visiting the site of the blast.

Zapatero said the attack made him more determined than ever to end ETA's campaign of violence but he announced no new strategy.