LAHORE: Country’s most populated province of Punjab on Friday extended school closures in smog-hit major cities by a week, as the country battles record air pollution.

“The schools will remain closed for another week due to the hazardous air quality. Institutes including universities would switch to online classes to ensure the safety of students,” Marriyum Aurangzeb, Punjab’s environment minister, told a news conference.

Air quality in Lahore was deemed “hazardous”, according to data by from IQAir, with the concentration of deadly PM2.5 pollutants — fine particulate matter in the air that causes most damage to health — around 30 times the level deemed acceptable by the World Health Organisation.