More than 25,000 Canadians have been forced to flee their homes as wildfires burn through thousands of acres, sending smoke down south into Minnesota and parts of the U.S.

Much of northeastern Minnesota remains under air quality alert Friday, while a second alert covering the northwestern part of the state will go into effect on Saturday.

As dozens of wildfires continue to burn across Canada, flames are sending far-reaching plumes of smoke into the sky and unhealthy air to distant places. Some of the more gigantic blazes have been delivering thick smoke that spread southward into the United States over recent days.