York Regional Police are searching for a suspect and witness following a sexual assault that took place near a Newmarket GO bus terminal early Friday morning.

According to police, the 18-year-old victim was heading westbound around 3 a.m., walking along a pathway that runs parallel to Davis Dr. from the GO station, when she was approached by a man. The man grabbed her, forced her to the ground and sexually assaulted her.

Another man interrupted the assault and interacted with the victim, but left the scene before police arrived. Investigators are appealing to the witness for information.

The suspect is described as 30 to 40 years old, about five-foot-nine with a lean build, and was wearing a covering over his face.

Anyone with information is asked to call the York Regional Police Special Victims Unit-Sexual Assault Section at 1-866-876-5423, ext. 7071 or Crime Stoppers at 1-800-222-8477.