Police are seeking witnesses after three women suffered head and facial injuries inside the Courthouse nightclub in Athol Street, Douglas, in the early hours of Sunday.
Two of the victims required hospital treatment.
A man has been arrested in connection with the incident, which took place at 1.25am, and is on police bail.
Detective Sergeant Bobby Syme from the CID said: It is known that a glass has been used in this assault, which has resulted in two females receiving non-life threatening head and facial injuries.
’The CCTV shows that there were a large number of people in the nightclub at the time so I’m appealing for anyone who was in the club and saw this incident to please get in touch on 631212.’