A woman was sexually assaulted by a man in a mask after she got off a bus in Richmond Hill in the early hours of Thursday morning, York Regional Police say.

Yonge Street and Canyon Hill Avenue area of Richmond Hill

York Regional Police are investigating after a woman was sexually assaulted shortly after she exited a bus in the Yonge Street and Canyon Hill Avenue area of Richmond Hill. (Charlsie Agro/CBC)

The incident occurred in the Yonge Street and Canyon Hill Avenue area at about 12:30 a.m.

Police say the victim was taken to hospital where she was treated for injuries.

So far, police have revealed that the male suspect wore a grey ski mask and had dark-coloured clothing on.

On Thursday, police sent in a search-and-rescue team to comb through a nearby field.

Anyone with information is asked to contact investigators at 1-866-876-5423, ext. 7071.

Information can also be passed on through Crime Stoppers at 1-800-222-8477.

With files from the CBC's Charlsie Agro