Tens of millions under air quality alerts in US as Canada fire smoke drifts south

Eastern US states including New York, Massachusetts and Connecticut issue alerts as hundreds of wildfires burn in Canada

• Canada wildfires smoke: latest updates

Tens of millions of people in the US were under air quality alerts on Wednesday, as smoke from Canadian wildfires drifted south, turning the sky in some of the country's biggest cities a murky brown and saturating the air with harmful pollution.

States across the east, including New York, Massachusetts and Connecticut, issued air quality alerts, with officials recommending that people limit outdoor activity.