At least 18 people were injured, including four critically, in a stabbing attack at a train station in Germany on Friday, authorities said. The suspect in the stabbing -- a 39-year-old woman -- has been arrested, police said. A magistrate has ordered the suspect to be placed in a psychiatric institution, Hamburg police told ABC News on Saturday.

A woman allegedly stabbed 18 people at Hamburg Central Station, leaving six in life-threatening condition. The suspect was arrested, and investigations are ongoing.