LAHORE, Pakistan — Smog has continued to blanket Punjab’s major cities, with the Air Quality Index (AQI) value reaching 424 today (Friday).

Residents who were suffocating on the noxious pollution appealed with officials to intervene. In recent years, Pakistan’s air pollution has increased as a combination of low-grade diesel emissions, smoke from seasonal agricultural burn-off, and lower winter temperatures merge into stationary smog clouds.

Lahore, a busy megacity of over 11 million inhabitants in Punjab province near the Indian border, has routinely ranked among the world’s most polluted cities.

Residents have attempted to clear the air by building their own air purifiers and filing lawsuits against government officials in recent years, but authorities have been hesitant to act, blaming the haze on India or saying the data are overstated.