11 March 2004 Madrid train bombings

The 2004 Madrid train bombings (also known in Spain as 11-M) were nearly simultaneous, coordinated bombings against the Cercanías commuter train system of Madrid, Spain, on the morning of 11 March 2004 – three days before Spain's general elections. The explosions killed 192 people and injured around 2,000. The official investigation by the Spanish judiciary found that the attacks were directed by an al-Qaeda-inspired terrorist cell, although no direct al-Qaeda participation has been established. Though they had no role in the planning or implementation, the Spanish miners who sold the explosives to the terrorists were also arrested.

Controversy regarding the handling and representation of the bombings by the government arose, with Spain's two main political parties—Spanish Socialist Workers' Party (PSOE) and Partido Popular (PP)—accusing each other of concealing or distorting evidence for electoral reasons. The bombings occurred three days before general elections in which incumbent José María Aznar's PP was defeated. Immediately after the bombing, 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 as a consequence of the PP government taking Spain into the Iraq War, a policy extremely unpopular with Spaniards. Following the attacks, there were nationwide demonstrations and protests asking the government to tell the truth. The predominant view among political analysts is that the Aznar administration lost the general elections as a result of the handling and representation of the terrorist attacks, rather than because of the bombings per se.