MADRID, Spain (CNN) -- Two car bombs exploded in Spain's northern Basque region early Sunday, and the second one injured seven people, a Basque regional police spokesman told CNN.
The first bomb -- in the Basque political capital of Vitoria -- was preceded by a warning call in the name of Basque separatist group ETA, and police cleared the area around a local bank.
No one was injured in that blast around midnight (6 p.m. ET Saturday).
But there was no warning call before the second car bomb -- near a police station in the Basque coastal town of Ondarroa.
Three Basque police officers and four civilians were injured and taken to hospital, said the police spokesman, who by custom is not identified.
Police also suspect ETA in the second blast, the spokesman said. There was extensive damage from both blasts, which are under investigation.
ETA is blamed for more than 800 deaths in its long fight for Basque independence and is listed as a terrorist group by the European Union and the United States.
The latest car bombs follow a week in which Spanish courts outlawed two leftist Basque political parties -- which have hundreds of elected town councillors and regional parliament deputies -- for their secretive links to ETA.
The elected officials are expected to lose their seats. In a separate case last week, another court convicted 21 people whose work on behalf of ETA prisoners actually belied secretive links to the armed separatists themselves, the court said.
The court convicted the 21 of membership in a terrorist group, and sentenced most of them to eight years in prison, while three got 10 year-sentences.
The Sunday bombs also follow a failed attempt last Tuesday by ETA to blow up the car of a Spanish national police officer, authorities said.
The officer drove several kilometers to work in his private car with a bomb attached underneath it, but the bomb failed to detonate and was discovered when he arrived a police station in the Basque region.
Spanish authorities -- from the government to the courts to the police -- have tried to choke off support for ETA in recent years, with numerous arrests of ETA suspects, convictions at trial, restrictions on political activities of known ETA supporters and a clampdown on clandestine ETA financing.
In March 2006, ETA declared a "permanent" unilateral cease-fire, raising hopes for an end to nearly 40 years of ETA violence.
But an ETA bomb at Madrid's airport in December 2006 killed two men and caused heavy damage, and the Socialist government immediately ended the fledgling peace process. Yet ETA did not officially end its cease-fire until June 2007.
There are about 500 ETA convicts or suspects in Spanish jails and more than 100 more in French jails, authorities said.