Lahore, a Pakistani city with more than 13 million people, has closed schools and public parks, malls and offices after the air quality index (AQI) this week spiked to more than 400.

As per the  Swiss air tracking company IQAir, this level is considered as 'hazardous'.

Authorities in Pakistan’s Punjab province have imposed an “environmental and health emergency” in three cities – Gujranwala and Hafizabad in addition to Lahore – until the situation improves, its chief minister Mohsin Naqvi said this week, reports CNN.

“There shall be a limited movement of people to and from these areas by public and private transport,” a statement from Naqvi’s office said as quoted by the American news channel.

Interestingly, Naqvi’s government has also restricted the gathering of more than four people in one place.