The Cafetería Rolando bombing was an attack Conflict.Attack.DetonateExplode on 13 September 1974 at the Rolando cafe in Calle del Correo , Madrid , Spain which killed Life.Die.Unspecified 13 people and wounded Life.Injure.Unspecified 71 . Though no claim of responsibility was made , the attack is widely believed to have been carried out Conflict.Attack.DetonateExplode by the armed Basque separatist group ETA .