Three Syrian men suspected of planning an attack in Dusseldorf for the Islamic State group have been arrested in Germany.
Prosecutors say a fourth suspect, who informed officials in Paris about the plot, is already in custody in France.
The federal prosecutor's office said the three men were arrested in three different German states on Thursday.
It said the plan called for two suicide attackers to blow themselves up in central Dusseldorf and then for further attackers to kill as many people as possible with firearms and explosives.
However, it says there are no indications that they had started with concrete preparations, and the plot was thwarted when one of the plotters went to French prosecutors on February 1 with details of the plan.