A bomb exploded early this in the small town of Leioa in Spain's northern Basque region after a warning call from the Basque separatist movement ETA.
There were no casualties from the blast opposite a car dealership, authorities said.
A spokesman for the Basque region's autonomous Ertzaintza police force said the bomb had gone off shortly after midnight, some 20 minutes after an ETA caller warned traffic authorities that it had been planted. Police had time to seal off the area.
ETA, branded a terrorist organisation by the United States and the European Union, has killed more than 840 people in a campaign spanning more than three decades for an independent Basque state in northern Spain and southwestern France.
This summer it has appeared to step up the frequency of its attacks, despite numerous arrests of alleged ETA members by Spanish and French police.
An ETA bomb ripped through the front of Santander airport last weekend only days after two bombs had blown up in the coastal resorts of Benidorm and Alicante, wounding 13 people.
