In two meetings held at the Baztan valley in Navarre in the summer of 2006, Txeroki, then head of commandos, ordered fellow ETA members Mattin Sarasola, Igor Portu and Mikel San Sebastián to carry out the bombing. The three members had been born in the Navarrese town of Lesaka and were part of the "commando Elurra" (), previously known as "Goiztiarrak", formed in 2002. Until 2006, the commando had the only task of helping members of ETA cross the Spanish-France border and transporting explosives. The cell was also linked with a car bomb attack against a discothèque in the town of Urdax on February 14, 2006, as well as with another attack against a discothèque in Santesteban on December 21, 2005. The leader of the commando group, Joseba Aranibar alias "Basurde" and Joseba Iturbide, who was also part of the cell, did not take part in the meetings. During the first meeting, Txeroki gave instructions on how to carry out the attack and told the members of the commando which secondary roads they should take to arrive to the airport and avoid being caught by security forces. After the meeting, Sarasola took part in the September 23 event along with Joseba Iturbide and an unknown member of the organisation.