Schools in Delhi have been asked to run hybrid classes for primary students and non-essential construction activity has been banned as air quality worsens in the Indian capital.
On Tuesday, authorities enforced stricter anti-pollution measures which include limiting movement of goods carriers in the capital and its suburbs.
Delhi's air quality has deteriorated to severe levels according to authorities, which can affect healthy people and seriously impact those with existing diseases.
On Wednesday, the capital's PM2.5 levels in the air reached 438, according to the Central Pollution Control Board - dangerously high concentrations of fine particles that can clog the lungs.
This is nearly 30 times higher than the World Health Organisation's safe limit and about eight times higher than India's national average. The WHO considers a 24-hour average of no more than 15 to be safe.
Doctors have advised people - especially children and the elderly - to avoid going outdoors unless absolutely necessary and to wear protective masks if they do.
Toxic air quality is a recurring problem in Delhi and across parts of northern India during the winter. There isn't a single cause behind the problem, but a mix of factors like low wind speeds, industrial emissions, vehicle exhaust, dropping temperatures, and the seasonal burning of crop stubble in neighbouring states contribute to the crisis.
On Tuesday, Saurabh Bhardwaj, a leader of the opposition Aam Aadmi Party (AAP), accused the Delhi government of manipulating air quality data and failing to protect public health. Chief Minister Rekha Gupta defended the government's efforts, emphasizing a commitment to pollution control.
