Police said a group of people had been celebrating at Deighton Working Men's Club on March 16, but the club in Deighton Road was still open to other members of the public.
Also in crime: Leeds detectives say suspicious men seen in Roundhay street before armed robbers assaulted woman in her homeThe trouble began at around 11.30pm when a fight broke out between a group of people in the pool room.
It spilled out of the pool room and continued outside the venue.
A West Yorkshire Police spokesman said the suspects had fled the scene.
"Four people were injured and two people - a man and a woman - needed hospital treatment," he said.
"Enquiries are ongoing to establish the circumstances."
Also in crime: Murder investigation halted after cause of attacked Castleford father's death revealedAnyone with any information about the incident, or who witnessed anything on the evening, is asked to call police on 101 and quote crime reference number 13180126504.
Information can also been passed to Crimestoppers on 0800 555 111.