April 3 (UPI) — Police in western Germany on Thursday night arrested a man armed with knives and pyrotechnic devices after he allegedly threatened to commit violence aboard a high-speed train, according to local authorities, who said a dozen passengers were injured.

The suspect, identified as a 20-year-old German man from Aachen, ignited two unknown pyrotechnic devices on an Intercity-Express train traveling from Aachen to Frankfurt at about 9 p.m., the Rhein-Sieg district police authority press office said in a statement.

Passengers on the train were able to detain the suspect and lock him in the train’s restroom. When police arrived at the Siegburg/Bonn station, officers arrested the man.

The train carrying about 180 passengers was evacuated and a section of the station was cordoned off, authorities said.

A search of the man discovered two knives and two additional commercially available pyrotechnic smoke devices.

At least 12 passengers sustained minor injuries in the incident and at least one person was transported to a Bonn hospital after suffering ear trauma.

A police spokesperson told German tabloid BILD that the suspect threatened to commit an unspecified attack.

“The investigation into his motive and the background to the incident is ongoing,” the Rhein-Sieg district police authority said in a statement.

Police are investigating the suspect on suspicion of dangerous bodily harm and violations of explosives and weapons laws.

The train and the affected track were reopened at around 12:45 a.m. Friday following a forensic examination of the crime scene, according to police.