Diners and drinkers at The Regal, in King's Square, watched on as a brawl broke out in the bar.
The argument, which was caught on camera on Thursday evening, was between a woman and two men. As the woman bawled, two men pushed and shoved each other on the staircase leading from the entrance.
A manager was forced to ask some of the people to leave.
Police officers attended shortly after and spoke to elderly diners nearby.
One diner said: "We were just having our dinner when all hell broke out. The woman was screaming at a man at the top of her voice and the whole bar could hear it.
"Then the men started pushing each other. It could quite easily have turned nasty."
VIDEO: A brawl breaks out in The Regal