Pakistan's eastern Punjab province has been struggling to combat an ongoing smog crisis, which is blamed for sickening 1.8 million people in the last month.

The U.N. children’s agency is warning that the health of 11 million children in Pakistan’s eastern Punjab province is in danger because of air pollution that experts say has become a fifth season in recent years.

Pakistan's province of Punjab set up a "smog war room" to tackle severe pollution, officials said, as poor air quality turned its capital of Lahore into the world's most polluted city and forced the closure of some educational institutions.

The United Nations Children's Fund (UNICEF) has raised concerns about the health risks facing 11 million children in Pakistan's eastern Punjab province due to worsening air pollution, which experts say has effectively become a "fifth season" in recent years.

Punjab authorities have banned most outdoor activities and told some shops to shut early as smog-induced illnesses soar. Schools have also been closed to protect children, who are at high risk from the pollution.