Madrid, Spain (CNN) -- Civil Guards arrested five Algerian men early Tuesday in northern Spain on suspicion of providing logistical and financial support for Islamic terrorist activities, Spain's interior ministry said.
The suspects, aged 36 to 49, allegedly supported "terrorist groups that operate in the Algerian area of the Maghreb, specifically for al Qaeda in the Islamic Maghreb," a ministry statement said.
They also had suspected links to Islamic militants in Italy, France and Switzerland.
Some 150 Civil Guards took part in the operation, making nearly simultaneous arrests and conducting searches of homes and premises linked to the suspects in two towns of northern Guipuzcoa province and two others in neighboring Navarra province, the statement said.
Computer hardware and software was seized and will be analyzed. Spain's National Court, which handles cases of terrorism, is supervising the operation, the statement said.
Spanish authorities have said repeatedly in the past few years that the group known as al Qaeda in the Islamic Maghreb is of key concern, because of its operational base in northern Africa, just across the Mediterranean Sea from Spain and southern Europe.
Last week, Civil Guards arrested a Cuban man on Spain's Mallorca Island in the Mediterranean for allegedly recruiting and indoctrinating others for Islamic terrorist activities.
A judge released the suspect from custody Friday, but he must report daily to police while authorities investigate computer documentation seized when he was detained.
Since the Madrid train bombings of 2004 that killed 191 people and wounded 1,800 others, Spanish police have arrested more than 400 suspected al Qaeda militants or collaborators, the Interior Ministry website says. Most have been of North African or Middle Eastern origin, with a few from Latin America.