The health of 11 million children in Pakistan’s eastern Punjab province is in danger because of air pollution, the UN children’s agency has warned.

Toxic smog has shrouded Pakistan’s cultural capital of Lahore and 17 other districts in Punjab since last month.

Health officials say more than 40,000 people have been treated for respiratory ailments.

Unicef’s representative in Pakistan, Abdullah Fadil, called on the government to make urgent and greater efforts to reduce air pollution for the 11 million affected children under the age of five and others.

A commuter train's headlights can just be seen as smog envelops an area of Lahore, Pakistan
A commuter train’s headlights can just be seen as smog envelops an area of Lahore, Pakistan (KM Chaudary/AP)

“Prior to these record-breaking levels of air pollution, about 12% of deaths in children under five in Pakistan were due to air pollution,” Mr Fadil said.

“The impact of this year’s extraordinary smog will take time to assess, but we know that doubling and tripling the amount of pollution in the air will have devastating effects, particularly on children and pregnant women.”

Pakistan has shut schools until November 17 in areas of Punjab as part of measures aimed at protecting children’s health.

Authorities on Friday ordered the closure of all parks and museums for 10 days, and they have been urging people to avoid unnecessary travel.

A cyclist, wearing a mask, heads to work amid the smog in Lahore
A cyclist, wearing a mask, heads to work amid the smog in Lahore (KM Chaudary/AP)

According to the Environmental Protection Department in Punjab, Multan remained the most polluted city on Monday, with air quality index readings of about 800. Anything more than 300 is considered hazardous to health.

Though the government has ordered the mandatory wearing of face masks, that has been widely disregarded. The government has also said it was looking into methods to induce artificial rainfall to combat the pollution.