Smoke from Canadian wildfires has prompted an air quality alert Tuesday for northern Minnesota.

The alert from the Minnesota Pollution Control Agency (MPCA) takes effect at 4 a.m. Tuesday and runs about 12 hours. It includes the northern half of Minnesota — as far south as Hinckley and Alexandria by Tuesday afternoon — and the tribal nations of Grand Portage, Fond du Lac, Leech Lake, Red Lake and Mille Lacs, the MPCA said.

"This air is unhealthy for sensitive groups, and pollution may aggravate heart and lung disease as well as cardiovascular and respiratory conditions," the MPCA said Monday. "Symptoms may include chest pain, shortness of breath, wheezing, coughing, and fatigue."

Those affected by the smoke are advised to limit their outdoor physical activities, take more breaks and scale back intense activities in order to reduce their exposure. "People with asthma should follow their asthma action plan and keep their rescue inhaler nearby," the agency said.

Air quality should improve across the northeast part of the state Tuesday afternoon but the smoke may linger across northwest Minnesota through Tuesday, the agency said.

The region affected includes Ely, International Falls, Roseau, Duluth, Brainerd and Moorhead.