Moroccan police have arrested a key suspect in the 2004 Madrid bombings and 2003 attacks in Casablanca, news reports said. Saad Houssaini, 38, was arrested for his alleged role in the Moroccan Islamic Combatant Group, according to Morocco's MAP state news agency. Citing security sources, MAP said he also went by the aliases Mustapha or Nabil and had been wanted since 2002. He allegedly headed the military wing of the group, known by its French acronym GICM, the report said. The report did not say when or where he was arrested. France's RFI radio and LCI television reported Friday that Houssaini was a mastermind of the Casablanca attacks and involved in the Madrid attacks. They said he was arrested in Casablanca on Thursday. Moroccan police officials could not immediately confirm the reports. No other details were immediately available. On March 11, 2004, a group of mostly North African Muslim extremists blew up four Madrid commuter trains, killing 191 people and injuring more than 1,500. Currently 29 people are on trial for their alleged roles in the attacks, including 15 Moroccans. The attacks in Casablanca killed 45 people, including 12 suicide bombers, and woke up the North African nation to the threat of Islamic terrorism. Questions remained around the identity of the suspect. Moroccan media reported a year ago that a Saad Houssaini, suspected co-plotter of the Casablanca attacks with links to the Madrid bombings, had been arrested along the Syrian-Iraq border and extradited to Morocco. Moroccan authorities never confirmed the reports. Moroccan media reports have said Houssaini helped make the bombs used in the Casablanca bombings. Earlier this week, the judge leading the Madrid investigation named a new suspect close to suspected ringleaders and asked Morocco to arrest him. That man was identified as Moroccan Abdelilah Hriz, 29.