NEW DELHI, Oct. 27 (Xinhua) -- Air pollution continued to worsen in the Indian capital Saturday, in spite of a sunny morning, prompting the environment authorities to advise people to stay indoors ahead of Diwali, the festival of lights.

In the morning, air quality index (AQI) was recorded at 332, considered very poor category. An AQI between O and 50 is said to be good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor and 401 and 500 severe.

Alarmed at the situation, the Central Pollution Control Board (CPCB) has recommended that people avoid heavy workouts, try to get themselves less exposed to toxic air, and cut down on the use of private cars.

"Pollution levels peak during Diwali every year mainly because of bursting of fire crackers by revellers. It's best to stay indoors for the next 10 days," an official told the media.

Delhi's air quality has been hovering between poor and very poor categories since Monday. Its neighboring cities like Noida, Greater Noida, Ghaziabad, Gurgaon and Faridabad have also been experiencing high pollution levels for the past six days.

State-owned System of Air Quality and Weather Forecasting And Research (SAFAR) which monitors pollution levels has predicted very poor air quality in Delhi in the next week too.

Delhi's Environment Minister Imran Hussain had Tuesday reviewed an action plan for implementing the Graded Response Action Plan (GRAP). GRAP kicks in when AQI touches severe levels as mandated by the country's Supreme Court.

The country's Supreme Court has already ordered a partial ban on bursting of crackers during Diwali to keep pollution levels lower than in previous years. The court ruled that people can burst "green firecrackers" from 8 p.m. to 10 p.m. only on Diwali.