One of the arrested in Spain allegedly praised the Boston Marathon bombings, but neither of whom was known to possess any explosives or be planning any attack. Interior Minister Jorge Fernandez Diaz said there was "sufficient grounds" to warrant the arrests, adding that they were made to avoid "greater risks". He said the two suspects were acting as "lone wolves".
Madrid is to stage its own marathon on Sunday. Authorities on Monday said that while no risk or threat had been detected, 1100 police and security personnel would be on duty.
Nou Mediouni, an Algerian, was arrested in the northeastern city of Zaragoza, while Hassan El Jaaouani, a Moroccan, was arrested in the southeastern city of Murcia. Officials are not aware of any connection between the two and had no information that they possessed explosives or were planning any attack.
They regularly visited an Internet website used by AQIM to recruit members. Mediouni had tried to travel to the north of Mali to be trained as a jihadist fighter but international police pressure prevented him from making the trip. Upon returning to Spain, Mediouni had expressed "frustration at not being able to 'die like a martyr'".
El Jaaouani, the Moroccan detainee, had made direct contact with a person in Mali suspected of having been involved with the kidnapping and killing of two French citizens in Niger in January 2011.
Police have been watching the two for the past year and had been working in conjunction with authorities in France and Morocco.
In August, Spanish authorities arrested two Chechens and a Turk, suspected Al-Qaeda members thought to have been planning an attack in Spain or elsewhere in Europe. On March 11, 2004, Spain suffered one of Europe's worst extremist attacks. Explosions on packed commuter trains in Madrid killed 191 people in bombings linked to Al-Qaeda.
Spanish police have arrested two suspected members of Al Qaeda in the Islamic Mahreb. An Algerian was caught in Zaragoza, the other, a Moroccan, in Murcia.
The two are said to have a "similar profile" as the two Chechen brothers that attacked Boston. They radicalized in a similar way. They visited forums and chatrooms on the Internet where they also got information of bomb construction.
Al-Qaeda in the Islamic Maghreb (AQIM) is the North African chapter of the terror organization. France and Spain have coordinated the operation. AQIM has threatened France because of its military intervention in Mali.