Federal prosecutors say police have arrested three Syrians who had planned to commit an extremist attack in central Dusseldorf on behalf of the Daesh group.
Germany's Spiegel Online also reported on the arrests Thursday without citing its sources.
The men were arrested in three different German states on suspicion of plotting to detonate an explosive device in the historic centre of Dusseldorf and then to kill as many people as possible with firearms.
A fourth suspect is in police custody in France, the Karlsruhe-based prosecutors said. The suspects are aged between 25 and 31.
German prosecutors and police have conducted a series of raids in recent months targeting Islamists sent to Germany on behalf of Daesh.
Thus far, there has been no major extremist attack on German soil.
