BERLIN (AP) — German prosecutors are charging a 34-year-old man who attacked passengers on a crowded city bus with a knife in the northern town of Luebeck on Friday with attempted murder.

Luebeck prosecutors said in a statement Saturday they're also charging the German-Iranian dual citizen with serious bodily harm and arson for trying to set the bus on fire.

The suspect, who wasn't identified by name, was arrested at the scene and remains in custody.

Ten people were injured in the attack, three of them seriously, including a 21-year-old Dutchman who was operated on overnight.

Prosecutor Ulla Hingst said the suspect hasn't spoken to investigators and his motive remains unclear.

German news channel Spiegel TV quoted the man's father as saying his son, who lived locally, suffered from psychological problems.