TORONTO -- Police are asking for the public’s assistance in identifying a man after a woman was sexually assaulted in downtown Toronto early Sunday morning.

Toronto police said they responded to a call about an incident in the Sherbourne Street and Dundas Street East area at around 4:45 a.m.

It was reported that a 22-year-old woman was allegedly approached by a man who produced a knife and attempted to rob her of money, police said.

Investigators said she was then forced into an alley where he allegedly sexually assaulted her.

Police said he was described as black with a medium complexion, was anywhere between 25 and 30 years old, stood five-foot-eleven, and had a medium to muscular build.

It was also reported that he had a wide face, was clean shaven and wore black pants and a black jacket with a white hood, police said.

Officers warned that he is believed to be armed, violent and dangerous, and asked the public to not approach him if located, and to call 911 immediately.