A 22-year-old man was seriously injured in a knife attack in Hamburg-Harburg early on Saturday morning. The police arrested three suspects, as a spokesman for the Hamburg situation center announced on Saturday. According to police information, the victim and the suspects are believed to be related. The attack was preceded by a joint celebration. There was an argument on the street and finally the knife attack. The 22-year-old suffered a stab wound to his upper body and was taken to hospital. There is no danger to life. The suspects are now being investigated for dangerous bodily harm, it said.