Officers found the teen on the sidewalk on Selkirk Avenue between McGregor and Powers streets at 11:30 a.m. Saturday, the police service said in a news release on Sunday. (Jeff Stapleton/CBC)

A 15-year-old boy was taken to hospital with a hammer still lodged in his head after being randomly attacked by a man on Saturday morning, police say.

Dakota Grozelle, 25, was biking with his brother in the North End when they stopped for pizza at a business on Selkirk Avenue near Andrews Street. As the pair were walking inside, Grozelle's brother gasped and told him to look in the entrance.

"We seen this guy laying on the ground with a hammer in his head," said Grozelle.

"It's kind of graphic but like, holy cow."

Dakota Grozelle, 25, was with his brother when they found the teen in the entranceway of a pizza shop on Selkirk Avenue Saturday morning. (Walther Bernal/CBC)

Grozelle said the employee in the store was on the phone, likely calling 911, so he and his brother stayed with the teen.

"He was talking to us," said Grozelle.

 "[My brother] was just trying to keep him awake."

Grozelle said he waved down police and made sure no one else tried to enter the restaurant.

Police say attack unprovoked

On Sunday, Winnipeg Police Service spokesperson Const. Rob Carver confirmed a hammer was used in the attack and said people in the area called 911.

Officers found the teen on the sidewalk on Selkirk Avenue between McGregor and Powers streets at 11:30 a.m., the police service said in a news release.

They found the teen suffering from serious head trauma, the release said. He was taken to hospital in critical condition and was still there Sunday morning. The teen is expected to have life-altering injuries, the release said.

Police believe the attack was unprovoked and that one man is responsible.

Anyone with information is asked to contact the major crimes unit at 204-986-6219 or Crime Stoppers at 204-786-8477.

Grozelle called the attack on the teen "devastating" and said he is often in the area picking up garbage and needles to keep the streets clean.

"It makes me feel more unsafe," he said.