The alleged assault took place between 2.30am and 2.50am in the town's Muir Street and officers have identified a man they want to speak to who was seen leaving the area via Bellshill Road.
He is described as having short hair, wearing a light blue top and grey jogging trousers.
Anyone with information is asked to call 101 and quote the incident number 0580.
Police are also looking for information on a break-in when two young black-clad males were seen entering a home in Myrtle Road, Viewpark, around 6am on Monday (September 20)
Anyone with information is asked to call 101 and quote incident number 0462.