Police on Tuesday searched dozens of sites in Germany linked to a mosque that was frequented by the Berlin market attacker Anis Amri, after authorities banned the Islamic group that operated it.Some 450 officers raided 24 locations in Berlin, the neighboring state of Brandenburg, and Hamburg in northern Germany starting at 6 am. In addition to the mosque itself they searched 15 apartments, two company offices and six prison cells. No arrests were made.Senior security officials said authorities had been watching the mosque for some time because of concern that it had become a meeting point for Islamic extremists. A previous attempt to ban the organization behind it, known as Fussilet 33, was aborted last summer.That decision was heavily criticized months later when it transpired that Amri had visited the mosque only an hour before driving a truck into a crowded Christmas market on Dec. 19, killing 12 people and injuring dozens more. Amri, a 24-year-old Tunisian citizen, was shot dead by police in Italy four days after the attack.Berlin’s top security official said authorities on Tuesday had seized funds belonging to Fussilet 33, shut down its website and imposed a blanket ban to prevent the organization from establishing itself under a different name or location.“It was necessary to ban the organization and all successor organizations to stop it once and for all,” Andreas Geisel told reporters. “People who preach hate have no place in this city.”Several people associated with the mosque, including leading members of Fussilet 33, had been arrested in the past on suspicion of supporting extremist organizations such as the Islamic State group and Jund al-Sham, said Geisel.The organization is alleged to have collected donations and helped recruit fighters for armed groups in Syria and Iraq.Documents and electronic devices seized during Tuesday’s raids were being examined to see whether members of Fussilet 33 knew of Amri’s plans, he said.“We currently have no indications that any further concrete attacks are planned in Berlin,” Geisel said.