Spain ? The prime minister toured the bombed wreckage of Madrid’s airport parking garage Thursday and warned the Basque separatist group ETA that neither the Spanish government nor its citizens will be intimidated.

Basque police, meanwhile, found about 200 pounds of explosives in a drum near an abandoned car outside the town of Amorebieta in northern Spain, a police spokesman said. It had been rigged to be used in an attack, the spokesman said.

Prime Minister Jose Luis Rodriguez Zapatero was escorted by police and firefighters as he visited the shattered concrete structure at the airport where a bomb exploded Saturday, killing one man and leaving another missing. ETA has not claimed responsibility, but the armed group is the only suspect in the bombing, which left the 9-month-old peace process in ruins.

“It will achieve nothing. It is not going to intimidate anyone,” Zapatero said.