PEMBROKE -- Police are investigating after a group of young people allegedly threw a rock at an 80-year-old Pembroke woman's head, vandalized her home and shouted racial comments.

Ontario Provincial Police say on Aug. 20, officers responded to a report that an elderly woman had been hit in the head with a rock in the area of Isabella Street and Rotary Park. The victim was treated in hospital and released.

"The investigation has revealed that the assault was part of ongoing harassment," police said in a media release Thursday morning.

"A group of young people had been committing vandalism to the victim's home and yelling racial comments."

The group of young people are described as 15 to 17 years of age. Police say at the time of the assault they were wearing shorts and baseball caps, and travelling on bicycles.

Ontario Provincial Police want to hear from anyone in the Isabella Street area, who has home surveillance video, specifically from Aug. 20 to 22.

Anyone with information can contact the Upper Ottawa Valley OPP at 1-888-310-1122.