Canada is battling more than 700 active wildfires across the country, roughly two-thirds of which are burning out of control, according to the Canadian Interagency Forest Fire Center (CIFFC). Smoke billowing from the blazes has blanketed central Canada and the northern U.S., prompting widespread air quality alerts.

At least twelve states have issued air quality alerts and advisories due to the ongoing Canadian wildfires sending smoke down to the Great Lakes region and the northeastern United States, the National Weather Service reported on Tuesday.

Health officials from Minnesota to Maine have issued alerts warning of poor air quality from wildfires burning in Canada. People are advised to limit outdoor exposure.