MONTREAL -- Four men have been arrested after a shooting in Old Montreal Monday morning.

Witnesses called 911 after gunshots were heard at 3:15 a.m. on Saint-Louis Street, near Gosford Street.

Officers recovered several shell casings at the scene, near Montreal City Hall.

Four suspects were identified, including a 29-year-old man, who was injured in the lower body.

The other suspects include two 25-year-old men and a 36-year-old man.

A security perimeter was set up in the area.

Traffic will be disrupted Monday morning as the exit from the Ville-Marie Highway to Saint-Laurent Boulevard remains closed.