Hundreds of uncontrolled forest fires blazed across Canada on Wednesday, threatening critical infrastructure, forcing evacuations and sending a blanket of smoky air wafting over U.S. cities, writes Reuters.

Wildfires are common in Canada’s western provinces, but this year flames have mushroomed rapidly in the country’s east, making it the worst-ever start to the season. About 3.8 million hectares have already burned, some 15 times the 10-year average, said Federal Minister of Emergency Preparedness Bill Blair.

“Across the country as of today, there are 414 wildfires burning, 239 of which are determined to be out of control. The giant eastern province of Quebec is among the worst affected. We’ve ... seen continued impacts to critical infrastructure in Quebec such as roads and rural closures, telecommunication interruptions and high voltage power lines being threatened by the growing fires”, - said Blair.

Quebec Premier Francois Legault earlier said the province was able to fight 40 fires at the same time: “But we have 150 fires so we have to make sure that we focus where the problems are the more urgent”.