Winnipeg police are investigating a triple shooting at what they're calling an illegal after-hours club in the city's Weston area.

Police said three men were at the club on Keewatin Avenue around 4:30 a.m. CT Sunday when an argument broke out between one of the victims and a suspect.

When the argument escalated, the suspect pulled out a gun and shot all three men in the lower body.

'It was just like a boom — that's all I heard — a big boom.'—Deanna Fontaine, neighbour

The three men were taken to the Health Sciences Centre's emergency room, where police found them.

Deanna Fontaine, who lives across the street from the club, said she woke up on Sunday morning to a loud bang.

“It just like a boom — that’s all I head — a big boom,” said Fontaine.

The next morning, she saw police tape surrounding the club.

People living in the area told CBC News the after-hours parties began about two months ago and often ran until 6 a.m.

A source who was inside the club on Sunday night said alcohol was for sale, and about 100 people were there when the shots rang out.

Police are warning people to stay clear of illegal clubs because they may not be up to safety standards.

"Basic sprinkler systems, safety doors, fire exits may not be in place," said Const. Eric Hofley.

Hofley added that anyone caught operating an after-hours club could be fined $240.

All three men survived the shooting, and the police service's major crimes unit is investigating. There have been no arrests made in the case to date.

Anyone with information is asked to contact investigators at (204) 986-6219 or Crime Stoppers at (204) 786-8477.