Calgary police are asking the public for help in identifying a man believed to have sexually assaulted two teenagers in Fish Creek Park.

The first assault happened around 7 p.m. on June 11, police said, when a 16-year-old male was riding his bike along a pathway in the provincial park, near the southwest community of Evergreen.

When he got off his bike to take a rest, the teen was approached by a man who struck up a conversation.

Police say a man sexually assaulted two young males riding their bikes in the Fish Creek area. (CBC)

"The man began asking inappropriate questions and then proceeded to sexually assault the teenager," police said in a release on Wednesday.

"The victim was able to get back on his bike and ride away to safety."

2nd incident similar

Then, two and a half weeks later, police received a report of a similar incident in the same general area.

Around 6:50 p.m on June 29, a 15-year-old male was riding his bike through Fish Creek Park near the Marshall Springs exit when he, too, was approached a man.

"The man engaged the teenager in a conversation and then proceeded to sexually assault him," police said.

"The victim was able to push the man away and ride to safety on his bicycle."

Police believe the same man is behind both assaults. They're looking for help in identifying the offender.

One of the assaults happened in Fish Creek Provincial Park near the Marshall Springs entrance, according to police. (Google Maps)

Staff Sgt. Melanie Oncescu said police didn't go public about the assaults until now because they were employing other investigative strategies.

"Initially, we had some leads that we were pursuing … and then, unfortunately, we've reached sort of a road block," she said.

"Unfortunately, we don't have any witnesses separate from the victims, so that's why we're seeking the public's assistance in trying to identify this individual."

Description of suspect

"The suspect is described as being Southeast Asian, 25 to 35 years old, between five feet seven inches and five feet 10 inches in height, with a slim build and a haircut that was short on the sides and medium-length on the top," police said in the release.

The suspect had a black and blue mountain bike in both incidents, police added.

Staff Sgt. Melanie Oncescu speaks to reporters about the sexual assaults. (Justin Pennell/CBC)

In the first incident, he was wearing grey shorts, a dark blue shirt, runners and a blue and yellow helmet.

In the second incident, he was wearing blue jeans, a short-sleeve blue shirt and black runners.

Anyone with information about the incidents or the identity of the suspect is asked to call police at 403-266-1234 or contact Crime Stoppers anonymously at 1-800-222-8477 or calgarycrimestoppers.org.