German police have carried out more than 50 raids to arrest suspected members of a banned Islamist extremist group styling itself as Caliphate State.
Three people were detained in the raids, which took place across six German states.
Caliphate State (Kalifatstaat) was founded in 1994 in Germany and was banned in 2001 for religious extremism.
During the raids, officers seized three firearms, propaganda material and more than €270,000 ($284,000).
"The German Regional Police struck against the so-called Caliphate State religious extremist organisation," said the EU's law-enforcement agency, Europol.
"During the action day, co-ordinated by the Landeskriminalamt Rhineland-Palatinate, officers raided 50 locations in a joint operation and arrested three individuals.
"The arrested individuals are suspected members of Caliphate State, which is a banned organisation in Germany."
Investigators are currently working on identifying international links.
Europol provided support by sending an expert to Germany to crosscheck operational information against the agency's databases and provide links to investigators in the field.
The extremist group had more than 4,000 members when it was disbanded.
"The members of this well-structured illegal network, which is widely spread across Germany, focus on radicalisation and collection of funds," Europol said.
"One of the prominent figures, son of the founder of the organisation, was arrested in Germany and extradited to Turkey in 2004, where he was jailed."