Julio César Castillejo Pérez was in the Haizea Bar with four colleagues from the Traffic Brigade. He was off duty and dressed in civilian clothes. Three terrorists armed with machine guns stormed the premises, planning to kill as many people as possible. Two others waited outside. They opened fire, killing four of the five officers and another customer who was in the bar at the time. They then shot them again as they lay on the ground. Another six people were wounded in the brutal attack. Judging by the shell casings later gathered in the bar, the terrorists are thought to have fired about sixty shots.
Also killed along with Julio César Castillejo were lance corporals Arturo López and Ángel Retamar and civil guard Modesto García. Another officer, Nicolas Martin, was seriously injured but survived. Together with the members of the Civil Guard, hairdresser Miguel Lasa was also killed and four other local people from Zarauz were injured.
On the next day, a day of protest was held in Zarauz and bars and shops were closed. The town council passed a resolution condemning the attack with the unanimous support of all councillors, including those from Herri Batasuna.