Winnipeg police are looking for a man following a sexual assault on a downtown street Friday evening.

A 29-year-old woman was walking in the area of Portage Avenue and Furby Street around 10 p.m. on Friday when she was confronted by an unknown man.

Police said the man approached the woman from behind, causing her to fall to the ground. The suspect then pinned the woman down and groped her in the upper body.

The suspect fled on foot after the woman began to scream and a passer-by tried to help, said police.

The man is described as having a dark complexion, 5 feet 10 inches (178 cm), heavy build, wearing a dark puffy jacket and neck warmer covering his face.

Police are still investigating and urge anyone with information to call investigators at 204-986-6668 or Crime Stoppers at 204-786-TIPS (8477).