New Delhi CNN  — 

Residents of India’s capital are set to suffer record-levels of smog for at least a week, even as the local government puts in place emergency measures to try and tackle New Delhi’s heavily polluted air.

Flights were delayed and diverted from New Delhi’s international airport Sunday when pilots could not see through the thick smog, which was more than three times the “hazardous” level on the global air quality index (AQI).

On Monday, the AQI level remained above 800 in certain parts of the city, the worst levels seen in more than three years. The Indian Meteorological Department said that while some of the cooler weather which has been exacerbating the smog will improve in the coming days, it is difficult to say whether this will lead to a substantial reduction in pollution.

Vehicles wait at a traffic light amid heavy morning smog in New Delhi on Sunday, November 3.

A public health emergency has been declared in New Delhi, where authorities have halted work at construction sites and instituted new traffic controls limiting the number of cars on the road. Schools have been closed and most residents who can afford to are staying home, though working class Delhiites are left with little choice but to venture outside.

Measures taken in the capital itself are unlikely to have a major effect on the smog however, as much of it is being generated by crop burning in areas around New Delhi, where farmers light fires to get rid of leftover crops and “stubble.”

Previous efforts to crack down on this seasonal issue – for example, by providing farmers with subsidized equipment that would mean they do not have to burn leftover crops – have been unsuccessful.