Pakistan's second-most populous city Lahore has shut down due to toxic air.
CNN reported that schools were shut and public parks, malls and offices were closed after air quality index (AQI) in the city spiked to over 400, a number considered "hazardous" by the Swiss air tracking company IQAir.
Chief Minister of Punjab Province Mohsin Naqvi said that an "environmental and health emergency" has been imposed in three cities of Gujranwala, Hafizabad and Lahore until the situation improves.
"There shall be a limited movement of people to and from these areas by public and private transport," a statement from Naqvi's office said Tuesday. Navqi's government has additionally restricted more than four people from gathering in a single place.
Colder temperatures trapped pollution particles, creating a toxic haze that reached hazardous levels reported by CNN.
Traditionally, toward the end of the year after the winter harvest, millions of farmers clear their leftover rice stubble by setting fields alight to prepare for the incoming wheat crop. This, combined with vehicular and industrial pollution, has resulted in copious amounts of smog.
On Thursday, the concentration of PM 2.5, or tiny particulate matter, in the air approached 450 in Lahore, which is 30 times higher than the World Health Organization's recommended maximum average daily exposure and considered hazardous reported Al-Jazeera.
On Friday there was some respite for the residents of Lahore as rain showers resulted in a considerable drop in air pollution.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)