Nottinghamshire Police attended the scene to investigate the incident at Weekday Cross, the BBC reported.
The video, which was filmed outside Nottingham Contemporary, made employees at the centre feel ‘scared for their lives’.
One man was shown wielding a large zombie-style knife before putting it back into its sleeve after, as three people ran down the steps by the side of the gallery.
A woman was seen on the video and she appeared to be trying to break up the group.
Three people, wearing dark clothes with heads covered, are seen to be carrying machetes.
One worker, who says the brawl started at 12.30pm said they were lucky there were no visitors in the gallery and locked the door as the gang ran away, adding ‘I was scared for my life’.