About five people have been injured in an axe attack in Duesseldorf’s main railway station, police say.
The attack happened at about 21:00 local time on Thursday (20:00 GMT).
Two arrests were made, and police have not ruled out the possibility that more attackers are still at large. There are no reports of fatalities.
Images shared on social media from the scene showed that the station had been cordoned off by police, and helicopters hovered overhead.
Witnesses reported seeing injured people lying on the ground.
A reporter for German newspaper Der Speigel at the scene said the situation was returning to calm.
Emergency vehicles filed through Konrad Adenauer square outside the station entrance.
Duesseldorf’s Hauptbahnhof is the city’s primary railway station, serving a quarter of a million passengers daily.