BERLIN — An assailant stabbed people at the central railway station in the German city of Hamburg on Friday, injuring 12 people - six of them critically, authorities said.

The person attacked people with a knife on the platform between tracks 13 and 14 in the station, according to police. They said on social network X that a suspect was arrested, but didn’t give details.

Hamburg’s fire service said that six people sustained life-threatening injuries, while another three were seriously injured and three had slight injuries, German news agency dpa reported.

The station in downtown Hamburg, Germany’s second-biggest city, is a major hub for local, regional and long-distance trains. Police cordoned off part of the complex.