Policeman Pinuel-Villalon was trapped under the rubble
A policeman was killed and four people injured when a car bomb exploded in Spain's northern Basque region.
No group has said it carried out the attack, but the region's governor blamed the Basque separatist group Eta.
Juan Jose Ibarretxe said the group was ruining the name of the Basque people with its campaign of violence.
The bomb exploded outside a police barracks in the small town of Legutiano, near the Basque regional capital Vitoria.
If confirmed, it would be Eta's first fatal attack since Spain's general election two months ago, and the sixth since Eta broke a ceasefire in 2006.
"I want to tell Eta not to ruin the name of the Basque people by using us as an excuse for extortion and murder," Mr Ibarretxe told reporters.
"We're sick of your violence," he added.
The dead man, named as Juan Manuel Pinuel-Villalon, 41, died after being trapped under rubble.
Dozens of people were evacuated from the scene of the blast
Four other people, civil guards and police, were wounded. One is said to have serious injuries.
Parts of the roof of the barracks were blown off in the pre-dawn blast.
Some 40 people, including women and children, were in the compound when the bomb went off, officials said.
No warning was issued before the attack.
The bombing, 15km (9 miles) from Vitoria, comes as the country embarks on a new parliamentary cycle.
Eta had already staged several low-level attacks following the Socialists' election victory in March.
Eta was blamed for a bomb blast in April in the Basque city of Bilbao, which wounded seven policemen.
The group said it was behind the murder of a former Socialist councillor outside his home, two days before the 9 March general election.