The air quality in the capital deteriorated to an alarming level on a hazy Sunday, forcing Sri Lankan cricketers to cover their faces with anti-pollution masks in a Test match at Delhi's Feroz Shah Kotla stadium.

Amid hazy conditions, the second session of the third and final Test match between India and Sri Lanka was halted for few minutes.

On Sunday, Delhi-NCR inhaled toxins as at least seven out of 22 monitoring stations registered a "severe plus or emergency" level of air quality.

During the Sunday match, six visiting Sri Lanka players wore masks while fielding after the lunch session at the Feroz Shah Kotla Stadium.

Umpires discussed the issue with the players and the match was halted for about 15 minutes.

The Air Quality Index (AQI) measured in Delhi at 4 p.m. was 351 (on a scale of 0 to 500), and by 6 p.m. it reached 361. On Saturday, the AQI of Delhi was 331.

At ITO, about two km from the cricket stadium, the air quality was "very-poor" with the major pollutant PM2.5 or particles with diameter less than 2.5 micrometers, was recorded 212 units -- over eight times the safe limit.

Meanwhile, Mathura Road in south Delhi recorded PM2.5 at 444 units -- over 17 times the safe limit considered "emergency or severe-plus".

Other areas with "severe" and "severe-plus" include Anand Vihar (PM2.5 434) in west Delhi was 434 units, Vasundhara (400) in Uttar Pradesh's Ghaziabad, Delhi Technical University (347) in north Delhi, R.K Puram (318) in south Delhi, Sector 125, Noida (373) in Uttar Pradesh and Shadipur (257) in west Delhi.

According to weather analysts, sudden increase in the moisture in air is a reason behind the dip in air quality.

"The wind directions changed here from dry and cold north-westerly to moist and cold south-easterly. The wind speed were low thereby increasing the pollution levels here," Mahesh Palwat, director, private weather forecasting agency Skymet, told .

The Met however has forecast light rains towards December 6 (Wednesday) which may bring down the pollution levels here.

However, according to the System of Air Quality and Weather Forecasting And Research (SAFAR), air quality is set to deteriorate over the next three days. 

While the national capital has been inhaling toxins since last 57 days as air quality had been varying from "poor" to "severe-plus", SAFAR had been suggesting public to wear masks, adding, "masks known as N-95 or P-100 respirators may only help if you go out".