On the morning of December 29, Aranibar gave the van to Sarasola and San Sebastian. Following the route they had planned, Sarasola drove the van while San Sebastián was driving a motorbike in front of the van. Meanwhile, Portu arrived with another vehicle to a point located 50 kilometres from the airport. Portu met Sarasola and gave him the equipment he needed in order to disguise himself. At 6:51 pm, Sarasola parked the van in the unit D of the Terminal 4 car park and triggered the bomb. He then took a taxi to the town of San Sebastián de los Reyes, where he got rid of the disguise. From there he took another taxi and met Portu, who was driving San Sebastian's motorbike. They then met San Sebastian and they all went back to Lesaka. On the next day, Portu went to the city of San Sebastián, from where he made the warning calls.