A powerful car bomb that authorities blamed on the violent Basque separatist group ETA exploded early Wednesday outside a police barracks in the northern Spanish city of Burgos, injuring dozens of policemen and their family members, a police spokeswoman said, according to New York Times.

The was no warning call ahead of the explosion, which occurred just before 4 a.m. as some 90 police and their families slept in the barracks, according to the spokeswoman, who spoke on condition of anonymity in line with police rules.

The blast injured 46 people, including six children, none of them seriously, she said. It sent the car flying into the air and shattered windows in nearby houses.

Television images showed charred wreckage from the car presumed to have caused the blast and gaping holes across the façade of the tall brick building, where windows had been blown out. One neighbor, who was interviewed by Spanish National Television, said she was thrown from her bed by the blast.

ETA, which is considered a terrorist group by the U.S. State Department and the European Union, has killed more than 825 people during its decades-old violent campaign for an independent Basque homeland.

The group, which frequently targets the police, was blamed for a car bomb that killed a policeman last month as he got into his vehicle just outside the Basque city of Bilbao.

A car bomb near a police barracks in Legutiano, in the northern Basque region, in June last year killed a policeman who was on guard outside. Members of the civil guard, which is a rural police force, often live in barracks.

ETA declared what it called a permanent cease-fire in 2006, but reverted to violence within months after peace talks with the Spanish government went nowhere.