ROSEAU, Minn. — Fire crews are getting the upper hand on a northern Minnesota wildfire.

According to the Minnesota Incident Command System's website , the fire in Roseau County was 90 percent contained Tuesday morning.

The fire is in the mop-up and monitoring phase after burning about 3,800 acres of marsh grass, lowland brush and scattered aspen.

Authorities say no structures were threatened and no injuries reported. The cause of the fire is under investigation.

The fire started Sunday about 15 miles northwest of Greenbush. A cold front that brought rain, clouds and cooler temperatures helped firefighters battling the blaze.