New Delhi, Dec. 23 -- Delhi's average air quality index (AQI) worsened further into deep red on Saturday, reaching 450 at 4pm, before it began improving, with officials saying some respite may be around the corner.

Authorities reviewed the situation and decided to hold back on lifting curbs on the use of old cars and private construction work, but acknowledged pollution levels were expected to improve beginning Sunday.

"The sub-committee, while comprehensively reviewing the air quality scenario and relevant aspects, noted that GRAP stage-III has just been invoked in the evening of December 22 and it's only reasonable to await the impact of the intensified preventive/restrictive actions, on the average AQI. Further, the forecasts also in...