German police on Tuesday searched more than 20 properties in Berlin with links to a mosque visited by the Tunisian asylum seeker who killed 12 people at a Christmas market.
About 450 officers have been searching apartments, two companies' premises and six prison cells connected to an organisation called "Fussilet 33 e.V.", which ran the mosque, since 6 a.m. (0500 GMT), police said in a statement.
"The cause for these raids is the fact that Berlin's state interior ministry has issued a ban against the 'Fussilet 33' organisation," Berlin police spokesman Winfrid Wenzel said.
Police said they have searched 24 properties and searches were ongoing.
"These 24 locations are above all apartments but also business addresses of those in charge of this mosque organisation. Also, a few cells at Tegel and Moabit prisons have been searched," Wenzel said.
Berlin state's interior ministry was not available to comment further when contacted by Reuters.
Andreas Geisel, interior minister for the state of Berlin, is due to give further details at a news conference at 1 p.m. (1200 GMT).
The federal prosecutor has said that Anis Amri, the Berlin attacker, visited a mosque run by the "Fussilet 33 e.V." organisation on the day of the December attack.
On Jan. 31 German police arrested three men on suspicion of having close links to Islamic State militants and planning to travel to the Middle East for combat training. Newspaper Bild reported that those men were frequent visitors at a mosque in the Berlin district of Moabit that Amri also used to visit.