Police here on Tuesday banned the mosque known as "Fussilet 33 e.V." which is believed to have links with extremists.

Policemen have closed down 24 branches of the association in Berlin, and more than 400 law enforcement officers participated in the operation, Deutsche Presse Agentur reported.

The praying rooms were reportedly the meeting places for Islamist extremists.

Anis Amri, the terrorist who carried out the Dec. 19 attack on a Christmas market in Berlin, visited one of the mosque organizations on the day he committed the crime, which killed 12 people and wounded over 50.

German police have been tightening up security in the wake of the attack.

Last week, authorities in Berlin arrested three men affiliated with the terror group "Islamic State." The men had also visited Fussilet 33 e.V.

Earlier this month, police also carried out a series of raids around Goettingen and arrested two men suspected of planning a terror attack.

Source: Xinhua