A video shorty after the attack.

He was killed when a car bomb exploded in a town near the northern city of Bilbao. Zapatero has called the police officer the latest victim of violence by the ETA rebel group.

Jose Luis Rodriguez Zapatero, Spain's Prime Minister, said, "He is the latest victim in a history of violence and horror inflicted by the terror group ETA. My first thoughts are for his family, who must know that they can rely on all the support and solidarity of the government and all the citizens. We are all with you in this moment of pain."

The 49-year-old victim was a member of the Spanish National Police. A bomb attached to the underside of his car detonated as he started the engine in a parking lot in the town of Arrigorriaga.

There has been no immediate claim of responsibility. But such bombings are a regular occurrence carried out by the Basque guerrilla movement, the ETA group.

If ETA's involvement is confirmed, this would mark the group's first deadly attack since the new government under Socialist President Patxi Lopez took power in the Basque region on May the 7th.