Police say that three men have been arrested in connection with the attack on the young male in south Belfast on Friday, May 3.
At around 4.15 pm yesterday police were called to reports of a disturbance at a flat on the Donegall Road.
Once inside they located the 17 year old victim injured and unconscious.
He has been taken to hospital where his condition is understood to be critical.
Detective Inspector Keith Wilson said: “The arrested males were detained at the scene and were taken to Musgrave police station for questioning. They remain in police custody this morning.
Anyone who can assist us with our investigation is asked to contact Musgrave CID on 101, quoting reference 1018 03/05/19.”