The bomb exploded outside the offices run by the Civil guard paramilitary police in Palmanova, just a few kilometres away from where the royal family were holidaying.
The incident came only a day after sixty five people were wounded in another explosion at a barracks in Burgos in northern Spain. Authorities say the two victims had been inside their patrol car when the bomb went off.
The hunt for the killers continues with the finger of blame being pointed squarely at ETA. While it has not yet claimed responsibility for the blast, the attack coincided with the group’s 50th anniversary of its founding.
Police later deactivated a second bomb placed under a car near to where the first device exploded.