The explosion caused the three-story building to collapse, crashing down on about 200 diners and employees, killing 18 people, all Spanish citizens, and injuring 82 others, including eleven Americans working at the nearby Torrejón Air Base who frequented the restaurant.
[8] After first blaming ETA, Spanish Interior Minister José Barrionuevo concluded the Islamic Jihad Organization and Wa'd had the most credible claim of responsibility following investigations by the National Police.
[1][4][2] The claim by Wa'd, distributed by the Kuwait News Agency was noted as it included the anagram of the sugar envelopes from the El Descanso restaurant.
[4][3] According to the El País newspaper and the Group of Strategic Studies, which cite the attack as "the first attack of Islamist terrorism in Spain," the credibility of Islamic Jihad eventually gained weight, also as a letter circulated two weeks after the bombing stated: "Islam is ready.
[4] In 1992 judge Baltasar Garzón made enquiries into the Marbella-based Syrian arms dealer Monzer al-Kassar who was linked to numerous crimes including the Achille Lauro hijacking, without results.