Smog on Thursday has continued to engulf provincial capital of Punjab as the Air Quality Index (AQI) went above 356.

As per the AQI, Lahore has declared as most polluted city in the world.

Residents choking in acrid smog pleaded with officials to take action. Air pollution has worsened in Pakistan in recent years, as a mixture of low-grade diesel fumes, smoke from seasonal crop burn off, and colder winter temperatures coalesce into stagnant clouds of smog.

Lahore, a bustling megacity of more than 11 million people in Punjab province near the border with India, consistently ranks among the worst cities in the world for air pollution.

In recent years residents have built their own air purifiers and taken out lawsuits against government officials in desperate bids to clean the air -- but authorities have been slow to act.