New Delhi, Nov 8 (IANS): The capital's citizens on Thursday struggled to breathe better air as pollution levels spiked across the city after Diwali, touching the "very poor" category.

According to the Central Pollution Control Board (CPCB), the Air Quality Index (AQI) for the Delhi-NCR (National Capital Region) region at noon was 361.

On Wednesday, Delhi's air quality oscillated between "poor" and "very poor" categories. At 5 p.m. on Wednesday, the AQI was 283 making it 'poor'.

On Thursday afternoon, System of Air Quality and Weather Forecasting And Research (SAFAR) recorded the AQI in Delhi at 554.

"Air quality index entered 'severe' category at 2 a.m on November 8 and will continue to remain so until evening," the SAFAR report said.

A smoke layer was formed over Delhi and the National Capital Region after 1 a.m. bringing down inversion layer and trapping pollutants rapidly," it said.

Surface winds have continued to play a major role, it said, as it was calm (2.1 kmph) on Thursday afternoon, so pollution levels were expected to build-up rapidly due to the stagnation.

"The contribution of stubble fire appears to be marginal so far," SAFAR stated.

It said the particulate matters PM2.5 and PM10 in Delhi-NCR was 450 and 578, respectively.

In its earlier report SAFAR warned that compared to last year, even if half the amount of firecrackers were burst this Diwali, the region's air quality was likely to go to up to "emergency" levels for two days with a spike in PM2.5 levels.

Despite the Supreme Courts directives, Delhi-NCR burst firecrackers on Diwali well past the 10 p.m. deadline that showed the AQI at a slightly improved level over last year.

The Supreme Court had limited the time for bursting crackers between 8-10 p.m. on Diwali, but people started just after sunset around 6 p.m. and continued well after 10 p.m. mark.