A bag containing explosives detonated at a government unemployment office early Sunday in the northern Basque city of Bilbao, slightly injuring a policeman, police said.
No one claimed responsibility for the blast, but police and Spanish media blamed the armed Basque separatist group ETA.
The device, made of 3 to 5 kilos (6 to 11 pounds) of explosives, caused important material damage to the building and its garage, said a police spokesman who spoke on condition of anonymity because force rules did not permit him to be quoted by name. The injured police officer was treated for cuts and bruises due to the explosion, the spokesman added.
The group was also blamed for setting of two small bombs outside a court house and a post office on Thursday in other towns in the Basque region in northern Spain.
ETA, whose name is a Basque-language acronym for Basque Homeland and Freedom, which regularly targets political party offices and businesses with similar devices as part of its near 40-year-old campaign for an independent Basque state, AP reported. V.A.