The PSNI were called to the premises on Francis Street at around 10pm.
One of the victims, a man in his early 20s, was stabbed in the stomach and was taken to hospital, but his injuries are not thought to be life-threatening.
The other victim, in his early 30s, required treatment for a hand wound.
Police in Co Down are also investigating an unconnected assault on a man in the Edenmore Road area of Mayobridge. The incident was reported at around 11pm.
A man was beaten around the head with what was thought to have been an iron bar. He was being treated in hospital.
A man in his 40s has been arrested.
