A slight improvement has been registered in the air quality of Delhi's as it shifted from severe to very poor on Friday. The overall air quality index (AQI) was 364 at 9.30 am.

The Delhi government has shared a NASA’s satellite image depicting "largescale stubble burning" in the nearby areas of the national capital. The justification came one day after Delhi's air quality went down from poor to very poor levels.

Despite a complete ban on stubble burning in Punjab, several farmers were seen burning their crop residue in the Amritsar region, saying they cannot find any other alternative to it.

The air quality of Delhi and adjoining areas on Wednesday again slipped into "very poor" zone and the experts say it will continue to remain so for at least next three days.

Air quality in Delhi and adjoining regions improved from "severe" to "very poor" on Wednesday as wind speed picked up due to western disturbance over north India and dispersed pollutants.

The air quality improved to 'poor' in the national capital and the regions around it on Thursday due to favourable winds, and is expected to get better over the next two days.

Wind directions changed by Tuesday noon, creating an outlet for the toxic air over the Delhi-NCR region and thereby improving the air quality to "very poor," from "severe" in the morning and "emergency" a day before.

With air quality in Delhi-NCR finally improving to "moderate" due to the meteorological conditions, the pollution monitoring agencies say it is the first December in three years when the national capital inhaled "normal" air.

US-based passenger carrier United Airlines on Saturday said it has temporarily suspended its Newark-New Delhi flights due to poor air quality concerns in New Delhi.

The alarming pollution in Delhi has led to at least 20 per cent increase in the number of persons complaining of cardiac/respiratory problems this week, officials said on Thursday.