Lahore | Dangerously poor air quality on Monday forced Pakistani authorities in the cultural capital of Lahore to close primary schools for a week, government officials said, after the air-quality index hit a record high over the weekend.

The measures in Lahore were part of a larger effort to protect children from respiratory-related and other diseases in the city of 14 million people. The government said everyone in Lahore was required to wear a face mask.

Fifty per cent of employees must also work from home as part of a “green lockdown” in the city, the government said, adding that barbecuing food without filters was banned and motorised rickshaws restricted.

Wedding halls must close at 10 p.m. and artificial rain is likely to be used to combat the pollution.

The air-quality index in Lahore exceeded 1,000 over the weekend, a record high in Pakistan.

Toxic gray smog has sickened tens of thousands of people, mainly children and elderly people, since last month when the air quality started worsening in Lahore, the capital of eastern Punjab province bordering India.

The government has also banned construction work in certain areas and fined owners of smoke-emitting vehicles. Schools will remain closed for a week because of the pollution, according to a government notification.

The concentration of PM 2.5, or tiny particulate matter, in the air approached 450, considered hazardous, the Punjab Environment Protection Department said.

Lahore was once known as a city of gardens, which were ubiquitous during the Mughal era from the 16th to 19th centuries. But rapid urbanisation and surging population growth have left little room for greenery.