MADRID, Sept 21, 2008 (AFP) - A car bomb exploded Sunday in Vitoria, the capital of Spain's northern Basque region, without causing any injuries following a warning from the Basque separatist group ETA, police said.

The car bomb exploded at midnight (2200 GMT Saturday) in the city's Salburua neighborhood, and police were able to clear the area before the blast after being alerted to its location in a coded warning from ETA.

ETA has waged a 40-year campaign for an independent Basque homeland that has claimed more than 800 lives.

The group was blamed for a bomb placed under a police officer's car last week, which was successfully defused.

ETA declared a 'permanent ceasefire' in March 2006 which it called off 15 months later citing a lack of progress in its tentative peace talks with the government of Prime Minister Jose Luis Rodriguez Zapatero.

Since the end of the ceasefire, ETA has killed four people and carried out a series of bombings, mostly in the northeastern Basque region.

Spanish police have detained dozens of suspected members of ETA and its supporters while Zapatero has repeatedly ruled out any further talks with the group.

Spanish authorities have also moved against parties with links to ETA's outlawed political wing Batasuna.

The Basque regional government's plans to hold a referendum on the self-determination for the wealthy northeastern region has been declared unconstitutional by Spain's Constitutional Court.