Eight people have been arrested in Spain and another in Germany on suspicion of working for a jihadist group in Iraq and Syria.
A Spanish interior ministry statement said police detained the eight in Madrid early on Monday on suspicion of recruiting jihadist militants for the Islamic State of Iraq and the Levant, or ISIS.
It said the cell was led by a person who live 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.
In Berlin, prosecutors' spokesman Martin Steltner said police arrested a 30-year-old Frenchman on Saturday suspected of "supporting a terrorist organisation" by fighting in Syria for the group.
Mr Steltner said the suspect, who was not named because of German privacy laws, was injured in fighting. He has also allegedly appeared in ISIS propaganda videos.
A court will decide on his extradition to France in the coming weeks.
European authorities have stepped up their cross-border co-operation since four people were killed in Belgium by a suspected French Islamic extremist returned from Syria.
Spain has arrested dozens of suspected jihadist militants in recent years, especially in its two North African enclaves, Ceuta and Melilla.