Police are investigating a disturbing incident in Brantford after a mother was assaulted while walking with a child.The woman was walking with a child in a stroller on the trails by the Grand River near the Lorne Bridge shortly after noon on Monday. A male who was standing with a group of men approached the woman, pulled her pants down and touched her buttocks. Police say the stroller was knocked over during the incident. Investigators say the woman and child were not physically injured. The group fled the area on foot. No suspect description has been released at this time. Anyone with information that could help police with the investigation is asked to contact Det. Michael Aasla of the Child Abuse and Sexual Assault Unit at 519-756-0113, ext. 3001.