Nearly 130,000 police and paramilitary security personnel have been deployed across the city, mostly in the New Delhi district, with the air force providing cover from aerial threats.

New Delhi reported 2,146 new infections in the past 24 hours and eight deaths, the worst figures among Indian states and federal territories.

Delhi accounted for more than 30% of the 2,067 new infections that India reported, taking the country's running total to more than 43 million.

Delhi's choking air put more children in hospital with breathing problems and the government shut five power stations and extended school closures to contain the crisis.

They say they have no choice but to carry on despite government advice to stay inside.

The order comes days after the Delhi government pushed back against a call by India's Supreme Court to declare a 'pollution lockdown' which would restrict the city's population to their homes.

Construction activity will be halted for four days to cut down dust, while government offices are asked to operate from home and private businesses advised to stick to work-from-home options as much as possible.

On Saturday, levels of harmful PM 2.5 particles topped 300 on the air quality index – more than 10 times the safe daily limit set by the World Health Organization.

While infections are falling in major cities, rural areas are seeing the brunt of a surge in cases that has overwhelmed the healthcare system.

India recorded 349,691 fresh cases and 2,767 deaths – the highest since the start of the pandemic.

Delhi's health system is at a tipping point, says chief minister.

Figures suggest the population may be approaching herd immunity levels.