BURGOS: The Spanish government accused the Basque separatist group ETA of targeting women and children in a powerful car bombing outside a police barracks in northern Spain which wounded more than 60 people.

About 120 people, one-third of them children, were sleeping inside the building in Burgos when the bomb went off at around 4:00 am (0200 GMT), blowing off most of its facade, Interior Minister Alfredo Perez Rubalcaba said.

The blast left a two-metre (six-foot) deep crater in the street outside the barracks which filled with water from broken pipes while the walls of several rooms were blasted off with damage visible to all 14 floors of the building.

Rubalcaba charged that ETA was "undoubtedly trying to kill" people with the bomb as it had not issued any prior warning as it often does when it strikes.

"It was not just aimed at those working in the Civil Guards but also at their families, which makes this particularly despicable. Forty-one children could have been killed," he said at the scene of the bombing.

"When we deal with ETA we know we are dealing with murderers and savages and now we know that they are also crazed. This does not make them stronger, but it does make them more dangerous," he added.

Of the 64 people who were wounded, 49 required hospital care, mostly for cuts from broken glass and bruises, and have already been released, the director of the regional health service, Francisco Javier Guisasola, told a news conference.

ETA, considered a terrorist organisation by the European Union and the United States, has frequently targeted the Civil Guard in its 41-year campaign to carve a Basque homeland out of northern Spain and southwestern France.

Prime Minister Jose Luis Rodriguez Zapatero vowed that those behind the attack would be brought before justice.

"All the state security forces are already working intensely to arrest these assassins. I am convinced that his craziness, the criminal fanaticism is scorned by all Spaniards," he told reporters.

The latest attack came just two days before the 50th anniversary of ETA's founding, on July 31, 1959, by nationalist students inspired by Marxist-Leninist teachings, at a time when Spain was still run by right-wing dictator Francisco Franco. It is blamed for the deaths of 825 people.

Spanish public television last month said a new road map of strategic plans by ETA reaffirmed its commitment to violence to achieve its aims.

"The terrorists believe that Basque independence is their irreversible goal. Only then will ETA no longer kill," TVE said, quoting a document that it said outlined the group's strategy put together over the past three years.

The newspaper El Mundo said on Sunday that security forces were on the alert after receiving information from France that ETA planned to bring three vans packed with explosives into Spain.

Rubalcaba said it was likely that the remains of what appeared to be a van destroyed by "a very powerful bomb" in Burgos had come from France, which has traditionally been used by ETA as a rear base to prepare attacks in Spain.

Media reports said the van contained at least 200 kilograms (440 pounds) of explosives.

Venezuelan President Hugo Chavez said the "terrorist attack" should "be roundly, energetically and firmly condemned.

"To those who carried out this terrorist act, lay down your bombs, lay down your guns," the leftist Venezuelan leader said.

In Argentina, Foreign Minister Jorge Taiana also condemned the bombing, expressing solidarity with the families affected.

"Once again we have to condemn in the most firm and unequivocal way this fresh attack against peace and civilized coexistence, which Spain has suffered," Taiana said in a statement.

The last ETA attack took place in early July when a bomb exploded in front of the office of the Basque Socialist party.

The last fatal attack blamed on ETA was on June 19, when a policeman was killed in a car-bomb blast near the Basque city of Bilbao.

In mid-2007 ETA called off a 15-month-old ceasefire following a deadlock in tentative peace talks with Madrid.

Since then the Socialist government of Prime Minister Jose Luis Rodriguez Zapatero has taken a hard line against it, repeatedly ruling out any new negotiations, while a string of operations by Spanish and French police have weakened ETA's leadership.