Winnipeg police are investigating five separate stabbing incidents, which sent seven people to hospital on Canada Day.

Const. Jay Murray said three men were stabbed during a large fight at a block party at St. Mary Avenue and Smith Street.

"It is a substantial investigation," he said, adding that the major crimes unit is investigating.

"Part of the investigation is the need to interview witnesses," said Murray. "I don't want to speak too much in regards to that incident just to prevent it from being compromised in any way."

Murray would not say how many people were involved in the fight or if any suspects have been identified.

At 12:15 a.m., officers came across a large fight that had erupted at a St. Mary Avenue and Smith Street block party. Three people are being treated for stab wounds. (Cliff Simpson/CBC) However, he did say an arrest was made in the stabbing at The Forks , which sent a 18-year-old man to hospital in unstable condition at around 7:20 p.m. on Saturday. A 19-year-old man was arrested.

"The suspect and victim knew each other, so it was not random stabbing at The Forks," said Murray.

He said in total, four of the five incidents were related to Canada Day celebrations.

At 12:45 a.m. Sunday, a 21-year-old woman was robbed and stabbed after getting off the bus from The Forks. This incident happened in the area of Arlington Street and Flora Avenue. Murray said there are two suspects, a man and a woman, but neither has been arrested.

At 1:30 a.m. Sunday, a man in his 20s went to hospital after being stabbed during a large fight at Main Street and Pioneer Avenue. Murray said the victim was leaving The Forks when the fight broke out. Police have identified two male suspects, but no arrests have been made.

Murray said the fifth incident was not Canada Day-related. A 22-year-old woman was stabbed in the 500 block of Sherbrook Street. He said a suspect has been identified in this case as well.

"I know from personal experience this one was a little busier than usual," said Murray.

"I believe we were expecting between 80 to 90 thousand people to partake in celebrations in the city," he said. "We did have additional resources and man power deployed in anticipation of increased crowds."

The investigations in all five incidents are ongoing.

Man tasered after coming off roof

At 6:30 a.m. Canada Day morning, police were called to a suspicious incident in the 1000 block of King Edward Street.

Officers saw a man acting erratically on top of the roof of a local business. They found the man at the business with injuries to his hands and upper body.

But when police officers approached the man, he became combative.

After a struggle, police used a Taser and took the man into custody.

Police said officers later found a knife hidden in his clothing.

A female officer was injured during the incident, but did not require medical attention.

The 21-year-old Winnipeg man has been arrested for causing a disturbance, resisting a peace officer, assaulting a peace officer and possession of a weapon.

Cadet struck by car

Police were directing traffic at Broadway and Main Street after the fireworks at 11:30 p.m. A cadet asked a woman in a vehicle to remain stopped because of the pedestrians in the area.

Police said the woman became belligerent and quickly accelerated her car, hitting the cadet. His arm was injured.

The suspect continued to drive away, but was quickly stopped by police.

A 31-year-old Winnipeg woman is facing charges of dangerous operation of a vehicle causing bodily harm, failure to obey a peace officer's directions and failure to remain at the scene of an accident.

Arrested with tire iron

Early Sunday morning police were patrolling downtown when they say officers saw someone trying to pry open the back door of a business.

They arrested a suspect around 2:30 a.m. and allegedly she had a tire iron in her possession.

A 20-year-old Winnipeg woman is charged with break and enter and possession of break-in instruments.