Eight people have been arrested in Spain and an additional three in Germany for suspected links with armed groups, especially in Iraq and Syria, authorities said Monday.
A Spanish Interior Ministry statement said police detained the eight in Madrid early Monday on suspicion of recruiting for armed group the Islamic State of Iraq and the Levant, or ISIL.
The ministry said the cell was led by an individual who lives in Spain but had previously been jailed in Guantanamo Bay after being arrested in Afghanistan in 2001.
Spain gave no immediate details on the nationalities of the arrested.
ISIL has seized large swathes of Iraq in a lightning campaign that has sent thousands of civilians fleeing for safety. The armed group ultimately aims to establish an Islamic caliphate encompassing modern-day Syria and Iraq.
In the past two years Spain has arrested several dozen people — both on the Spanish mainland and in the country's enclaves Ceuta and Melilla in northern Africa — accused of recruiting and training fighters to send to Syria and other conflict zones.
In Berlin, prosecutors' spokesman Martin Steltner said police on Saturday arrested a 30-year-old Frenchman suspected of "supporting a terrorist organization" by fighting in Syria for the group.
Steltner said the suspect, who wasn't named because of German privacy laws, was wounded in fighting. He has also allegedly appeared in ISIL propaganda videos.
A court will decide on his extradition to France in the coming weeks.
The French Interior Ministry said in a statement that the detainee had been identified by French intelligence agency DGSI as "dangerous and susceptible of acting on French soil." The statement said he was arrested upon arrival from Istanbul.
German police also arrested a 27-year-old German woman at Frankfurt Airport on Thursday, and a 17-year-old German in Stuttgart on Friday. Both are being linked to extremist groups.
European authorities have stepped up their cross-border co-operation since four people were killed in Brussels by a suspected French extremist returned from Syria.
The suspect in that shooting passed through Frankfurt Airport earlier this year, triggering an alert from German authorities to their French colleagues, but they didn't ask for his arrest.