A thick haze of polluted air hangs over India's capital as authorities try to tackle the problem by sprinkling water to settle dust and banning some construction.
The air quality index exceeded 400 on Tuesday, about eight times the recommended maximum, according to the state-run Central Pollution Control Board.
Favourable winds had briefly halved that measure of pollutants but winds blowing from the northwest carried emissions from burning crops in Punjab and Haryana states to New Delhi, leading to high levels of pollution, according to government air quality monitoring system SAFAR.
Air pollution in northern India peaks in the winter due to smoke from agricultural fires. Farmers say they are unfairly criticised and have no choice but to burn stubble to prepare their fields for the next crop.
Stringent pollution controls have been imposed, such as sprinkling water from high-rises and banning some construction to settle or avoid dust, but the worsening air quality in Delhi has remained persistent.
Restrictions on private vehicles meant to reduce emissions were relaxed Monday and Tuesday for 550th birth anniversary celebrations of Guru Nanak, the founder of the Sikh religion.
The pollution crisis affecting 20 million residents is also piling public pressure on the government to tackle the root causes of the persistent haze.
Doctors in the capital say many of their patients these days are complaining of ailments that stem from the filthy air they breathe.
Australian Associated Press