The bombings occurred three days before general elections Choosing in which incumbent José María Aznar 's PP was defeated .

Immediately after the bombing Use_firearm , leaders of the PP claimed evidence indicating the Basque separatist organization ETA ( Euskadi Ta Askatasuna ) was responsible for the bombings .

Islamist responsibility would have had the opposite political effect , as it would have been seen Causation as a consequence of the PP government taking Conquering Spain into the Iraq War , a policy extremely unpopular among Spaniards .