MADRID, Spain - Two car bombs blamed on Basque separatists went off in Madrid and in northern Spain on Tuesday, killing a businessman and injuring 11 other people.
The blasts came a day after four suspected members of ETA died when explosives they were handling exploded inside a car in the Basque city of Bilbao.
On Tuesday, Prime Minister Jose Maria Aznar went on television to denounce an attack earlier in the day in Zumaia, in the northern Basque region, that killed one man. Aznar promised to press the government campaign against terrorist violence.
Shortly afterward, a car bomb went off in a residential area of Madrid, injuring 11 people. Police said they received a telephoned warning minutes before the explosion from a man who claimed to represent the Basque group ETA.
One of the injured in Madrid was seriously hurt, city officials said. Police said the injured included two construction workers, a security guard and two children.
The bomb in Zumaia also was blamed on the ETA, which has killed nearly 800 people since 1968 and is blamed for eight slayings this year. Its ultimate goal is to carve an independent homeland out of Basque areas in northern Spain and southwest France.
''The murderers who are part of this terrorist band are not allowing the Spanish people to live in peace,'' said acting Madrid Mayor Mercedes de la Merced.
Deputy Prime Minister Mariano Rajoy called the Zumaia explosion an example of ''barbarity, injustice and lack of respect for the most fundamental rights that people have as human beings - life, freedom to do as they wish and to express their opinion.''
Authorities identified the victim in Zumaia as Jose Maria Korta, 52, an entrepreneur and an outspoken critic of ETA who had recently urged dialogue between the government and the separatist group.
Korta died near his office when he parked his car next to an explosives-packed car that was detonated by remote control, police said.
ETA is an acronym for Basque Homeland and Freedom in the Basque language.