The extreme right GAE terrorist group placed a bomb in the Aldana bar of Alonsotegi. There were four deaths: Manuel Santacoloma, Mari Paz Ariño, Pacific Fika and Liborio Arana. The explosion caused up to 20 wounded, some very serious and with amputated members. The Spanish Government ordered the investigation of the attack on José Amedo, later known for his membership in the GAL. The case was not investigated at all and has never been resolved.

The GAE is one of the denominations that the Spanish secret services used for the dirty war between 1975 and 1982, made up of extreme right-wing members. These groups killed at least 70 people in the Basque Country during this period.