After a short-lived relief, Delhi's air pollution levels inched towards the 'severe' zone due to calm winds, low temperatures and high humidity.
Experts said the situation is likely to worsen in the next 24 hours, with some relief expected on Saturday.
The AQI for Rohini (414), Anand Vihar (422), Nehru Nagar (410), Dwarka Sector 8 (404) and Bawana (407) entered the 'severe' zone.
Neighbouring Ghaziabad (415), Greater Noida (402), Noida (402) also recorded 'severe' pollution levels, while the AQI in Faridabad (391) bordered the 'severe' zone.
An AQI between 201 and 300 is considered 'poor', 301-400 'very poor' and 401-500 'severe'.
According to the India Meteorological Department (IMD), very low wind speed due to a western disturbance and high humidity due to shallow fog in the morning led to the accumulation of pollutants.
The Centre-run System of Air Quality Forecasting And Research said the relief is expected only on Saturday with an increase in wind speed, which will disperse pollutants faster.
"Though the farm fire count is relatively high (1,011) as compared to last week, transport-level winds (easterly) are not favourable for plume intrusion," it said.
Smoke from stubble burning accounted for just 5 per cent of Delhi's pollution. It is expected to reduce to 4 per cent. Delhi recorded a minimum temperature of 12.5 degrees Celsius.
Comprehensive plan for Delhi-NCR identified: Javadekar
Union Environment Minister Prakash Javadekar on Thursday said that a comprehensive air plan for Delhi NCR had been developed identifying the timelines for abating and controlling the air pollution.
"In order to abate and control air pollution in Delhi NCR, we have undertaken several initiatives. A high-level task force was constituted under the chairmanship of the Principal Secretary to the Prime Minister. Regular review meetings have been held," said Javadekar while speaking in the Rajya Sabha.
"A comprehensive air plan for Delhi NCR has been developed identifying the timelines and implementing agencies for actions delineated. Centre has notified a graded response action plan for Delhi NCR for different levels of pollution," he added.
Provide incentives to farmers for not burning stubble: LS members tell govt
Members cutting across party lines said in Lok Sabha on Thursday that stubble burning alone could not be blamed for rising levels of air pollution in and around Delhi and urged the government to provide incentives to farmers so that they disposed of stubble in a more scientific manner.
Some members also suggested that minimum support price should be extended on produce like pearl millet (bajra) and sunflower as after harvesting they do not leave stubble.
National Clean Air Programme: Tharoor suggests framework to fight pollution
Congress member Shashi Tharoor on Thursday suggested that a legislative framework be adopted to implement the National Clean Air Programme (NCAP), which proposes multiple measures to combat air pollution.
Speaking in the Lok Sabha, Tharoor said political differences should be kept aside as there was a need to work together to address this "toxicity".
"A legislative approach needs to be adopted to implement the NCAP," he said.