An early morning car bomb attack rocked a suburb of Madrid bringing back memories of the March 11th train bombings in the Spanish capital.
At least 40 people were injured in the blast but it could have been a lot worse. The police had time to evacuate the area following a tipoff from the Basque terror group that an attack was imminent.
The blast occured close to the convention centre where the King Juan Carlos and the Mexican President were scheduled to open an art fair.
The injuries were light, the damage extensive. New office blocks saw their windows shattered.
At least six police officers involved in the evacuation effort were hit by flying debris in the blast.
Its unclear if the attack was linked to a series of raids across Spain overnight.
Around 10 people accused of being connected to ETA were seized by anti-terrorist police in the Basque country and the city of Valencia.
ETA has waged a decades-long terror campaign for an independent Basque homeland on both sides of the Spanish-French border, but has been hit hard by a crackdown in recent years.