Three Syrian men who entered Germany as refugees were arrested Tuesday on suspicion of planning an attack on behalf of the Islamic State terrorist group, prosecutors said.
The men - aged 17, 18 and 26 - arrived in November posing as asylum seekers to "either execute an existing mission or to stand ready for further instructions" from Islamic State, the federal prosecutor's office in Karlsruhe said.
The Syrians were detained as part of a counterterrorism operation in which some 200 officers raided six locations in the states of Lower Saxony and Schleswig-Holstein, the Federal Criminal Police Office BKA said.
Prosecutors said that the three men were all arrested in Schleswig-Holstein, but have declined to confirm reports that the raids took place in refugee homes.
Interior Minister Thomas de Maiziere was scheduled to give a statement on the counterterrorism operation at 12:30 pm (1030 GMT).
Germany has been on high alert since two Islamic State-claimed terrorist attacks in the space of one week in July. Both attackers were asylum seekers.
Chancellor Angela Merkel has been the target of sustained criticism from her political allies for her promise of sanctuary to Syrians fleeing war, which led to hundreds of thousands of arrivals in the last four months of 2015.