Three people suspected of trying to reach foreign 'war zones' in Iraq and Syria to train for terror attacks have been arrested in Berlin.
A police spokesman said the suspects were aged 21, 31 and 45 and had planned to reach a terrorist training camp.
The three men detained attended the same mosque used by a Tunisian man suspected of perpetrating the Berlin Christmas Market truck attack just before Christmas. The attack, which killed 12 people, was subsequently claimed by Islamic State.
The mosque was also searched as part of the investigation.
Police have also arrested a Tunisian man in Frankfurt on suspicion of planning a terrorist attack, after a huge team searched homes, businesses and mosques.
More than 1100 police were involved in the operation, searching 54 homes, mosques and business premises in Frankfurt and towns in the state of Hesse this morning, Reuters reported.
Frankfurt's prosecutor general said the 36-year-old is suspected of recruiting for Isis since August 2015.
The authorities are currently investigating 16 people, including the arrested man. The suspects are aged between 16 and 46.
Interior minister for the state of Hesse, Peter Beuth, said: "It was not about preventing an imminent attack - rather security forces in Hesse intervened early to protect citizens from the threat of harm."
He also said that police were able to "destroy an extensive Salafist network." Salafism is an ultra-conservative branch of Sunni Islam.