Traffic is being rerouted during a Wednesday morning blaze.

Emergency crews are at the intersection of Portage Avenue and Langside Street. Heavy smoke began billowing out into the street before crews arrived at 9:38 a.m.

A two-story building in the 300 block of Langside Street has caught fire. At least two fire trucks are on the scene.

"A defensive attack was launched as it was not safe for crews to make entrance," the City of Winnipeg says in an emailed statement. 

They say aerial ladders are being used to fight the fire on the exterior, as it is not safe to enter.

The cause of the fire is unknown. The city believes the building was not occupied.

Westbound Portage Avenue traffic cannot get through.

"At this point, it is expected that crews will be on scene for an extended period of time. Portage Avenue is closed to traffic in both directions. Residents should avoid the area.," the City of Winnipeg says.

The City of Winnipeg's traffic Twitter account says they are rerouting people.

"Please follow the direction of police on scene," Winnipeg TMC tweets.