Stabbed in head.
It happened at about 3am yesterday at the City Gate apartment block in the May Street area.
Detectives are investigating reports that he was attacked after confronting four men at his car.
Police later discovered that four cars had been broken into.
The man sustained puncture wounds to the top of his head.
In Co Down, a 25-year-old man is recovering in hospital after being stabbed in the chest.
The incident happened at a flat at John Mitchel Street in Newry early yesterday.
He is not believed to be seriously injured and one man has been arrested.