At 6:20 pm (local time), unidentified individuals threw two fragmentation grenades into a public hallway leading to the main entrance of the United Services Organization (USO) facility… At the time of the attack there were 20 U.S. servicemen in the bar. The explosions fatally wounded one seaman and injured nine others. Two groups, Terra LLiure and the Red Army for the Liberation of Catalonia (ERCA), both claimed credit for the attack. This attack does not fit the modus operandi of Terra LLiure and it is believed that the ERCA was responsible.