Do you know this woman?
Officers say a 30-year-old female was grabbed by the hair, had a glass thrown at her face and was dragged to the floor in the attack.
The incident happened at around 1.30am on March 12 at Baluga in Miller Arcade, Preston.
Police say they would like to trace the woman in the CCTV image “as part of our ongoing investigation.”
PC Selina Hurst said: “This incident left the victim extremely shaken and with swelling to her face.
“We believe the woman in the CCTV pictures may be able to help with our enquiries and we are urging anybody who recognises her – or indeed the woman herself if she sees this appeal – to contact us as soon as possible.”
Anybody with information is asked to contact police on 101, quoting log number 969 of March 12.