Now police officers investigating want to speak to the trio and any other witnesses to the altercation in Garrison Square in the early hours of Thursday morning.
Two women left the Apollo Bar and walked to the square where they were assaulted between 2am and 3am.
It is claimed the attack was carried out by two women known to them and recorded by a man, who they also know, on his phone.
Three men are said to have intervened and the two women and man then left the scene.
Any independent witnesses – particularly the three men who broke up the altercation – are asked to call 101, quoting crime reference number 2194795.