VANCOUVER -- Vancouver police have issued a warning after they say a 17-year-old girl was sexually assaulted while walking home on Tuesday evening.

Police say the teenager was walking home after a sporting event at Churchill Secondary School around 6 p.m. on West 54 Avenue near Osler Street when she was grabbed from behind by an "unknown man." She was able to fight him off and run away, according to police.

"It's a very traumatic incident for her to go through, and we're glad she was able to fight her attacker off and get home," said Sgt. Aaron Roed.

"We're not trying to instill fear into the community, but we want everyone to know that this incident did happen and to be aware and that there is a male out there who committed this assault."

Police describe the suspect as "very tall" and say he was wearing all black clothing at the time of the assault.

The Vancouver School Board has put out a letter to students from Churchill and spoken to other schools in the area, according to police.

"Our school liaison unit is actively working in the school, working with students. We also have our victim services unit who is available if anybody does need to talk," said Roed.

Police are also encouraging students on the West Side to walk in groups and be aware of their surroundings.

Police are asking anyone with dash cam footage who was in the area of West 54th Avenue and Oak Street to contact them. They are also specifically appealing to people with factory surveillance systems in vehicles, such as Teslas, to reach out to police.

"These vehicles have running surveillance video which goes 24 hours a day, so it doesn't have to be specifically on, like dash cam footage where you have to push record," said Roed. "Teslas, and I believe other vehicles with this same technology, the video surveillance is continually running. So they might not even know they gathered the video footage, but it may be in their hard drives."

Anyone with information about this incident is asked to call Vancouver police at 604-717-0602.