CALGARY -- A teenager walking his dog with his mom Saturday night was stabbed in what appears to be a random attack.

Calgary police say the two were walking in an off-leash dog park near 110th Avenue S.W. and 14th Street S.W. around 7:50 p.m. when they came across a man and the teen was stabbed.

The man then ran from the Braeside neighbourhood into the community of Southwood.

The 15-year-old was taken to hospital in serious condition.

“They are serious internal injuries,” Staff Sargent Jeff MacQueen told reporters on Sunday. “I expect he’ll be in hospital for the next while recovering.”

The suspect is described as being between 40 and 50 years old. At the time of the assault, he was wearing dark clothing and a three-quarter-length jacket with reflective markings.

Officials said the attack appears to be random and investigators are still looking for the suspect.

“There was no threat or demand for money, (and) that’s what leads us to believe that this is somewhat random,” MacQueen said. “We are still trying to figure out what the motive was.”

MacQueen added, “The whole situation is quite concerning for us… hopefully we’ll start to get some answers in the coming days”

On Sunday, many dog owners at the park said the stabbing will make them extra cautious.

“Just the thought that you could be here just enjoying some time on Family Day weekend with your family, and next thing you know, you're stabbed for no reason... It alarms me quite a bit,” said Darren Dymsky.

MacQueen said there is currently no indication a similar attack could happen in the future.

Police are searching for security camera footage from the area and ask anyone who was in the area of Braeside and Southwood around that time and saw something suspicious to contact them at 403-266-1234 or Crime Stoppers at 1-800-222-8477.