The attacker targeted a Kurdish cultural centre and shot members of the local community. A possible racist motive is being investigated.
A suspect, aged 69, was quickly arrested and it soon emerged he had been freed from prison recently.
Clashes later broke out between police and a group who had gathered at the scene in the aftermath of the attack.
Footage showed people starting fires in the middle of the street and smashing car windows, with officers clad in riot gear responding by throwing tear gas.