It was initially reported that ETA, a Basque separatist group, was responsible for the bomb attack in Madrid, just days before the Spanish election. Some people think that ETA wants to disrupt the election as much as possible. Others think that it is not ETA's style to attack by explosion without saying hello in advance.
A series of explosions occurred in the residential area of office workers in the city, several of which occurred almost simultaneously, causing the biggest civilian casualties, which was completely different from the previous Basque separatist attacks. In addition, the scale of this explosion is larger than any previous attack made by ETA.
The Madrid bombing occurred 9 1 1 days after the attack on the World Trade Center in New York. People soon found evidence and began to suspect that Islamic terrorists were related to Al Qaeda. On March 4th, 2004, a video tape was found near a mosque in Madrid. In the video, a man who claimed to be the European military spokesman of Al Qaeda said that the Madrid bombing was in retaliation for "... cooperating with criminal Bush and his allies."
In the following weeks, Spain arrested suspects suspected of making explosions and having links with Islamic terrorist organizations. The Spanish government also applied for issuing an international wanted order to arrest 10 suspects living in other countries or regions.
On the third day after the explosion, a general election was held. Prime Minister Aznar and his People's Party tasted defeat and were defeated by the Socialist Party. Soon after, the new Prime Minister jose luis rodriguez zapatero announced plans to withdraw Spanish troops from Iraq. Many Spaniards who opposed the invasion of Iraq welcomed the decision to withdraw their troops.