Police have issued a warning to the public after a violent sexual assault near an East Vancouver park Wednesday.

Investigators said in a news release Friday that a woman in her 20s was walking on Matheson Crescent toward Southeast Marine Drive near Everett Crowley Park at around 8:30 p.m. when she was grabbed from behind by a man with a knife.

The suspect allegedly pushed her into some bushes and sexually assaulted her until an unknown a couple walking their dog intervened and scared the assailant off.

“We are thankful that this couple were there to help stop the assault,” Const. Jason Doucette said in the statement.

“They stayed with the victim to ensure her safety and even helped her get home.”

Authorities were informed about the incident the following day.

Now, police are asking to speak to the couple that intervened. Officers have not had a chance to speak to the Good Samaritans, Doucette said, adding that “it’s very important to our investigation that they come forward.”

"In my opinion, you're a hero. We'd like you to come forward. We'd like to hear your side of the story," Doucette told CTV News.

Area resident Christine Hillick said it’s "fantastic" that someone intervened, but is concerned for the safety of her daughters, who are also in their 20s.

"It does make me nervous because this street can be kind of dark…and there's not usually a lot of people around," she said.

Investigators are now looking for the suspect, who is described as a Caucasian man between 20 and 40 years old. He is 5-6 to 5-7, weighs about 170 pounds and has an athletic build. The man was wearing a tight black T-shirt, black pants and had his face covered at the time of the alleged assault.

Anyone who may have been in the area during the time of the incident is asked to contact the VPD’s Sex Crimes Unit at 604-717-0600 or Crime Stoppers anonymously at 1-800-222-8477 (TIPS).

With files from CTV Vancouver's Allison Tanner