New Delhi, Jan 17 : The National Capital Region (NCR) has once again come under the harshest anti-pollution restrictions as the Air Quality Index (AQI) surged dangerously close to the â??Severe+â?? category on Saturday.

The Commission for Air Quality Management (CAQM) announced the reimplementation of Stage-IV measures under the Graded Response Action Plan (GRAP), citing rapidly worsening conditions.

At 4 p.m., Delhiâ??s AQI was recorded at 400, already in the â??Very Poorâ?? range. Within four hours, it climbed to 428, approaching the threshold of 450 that marks â??Severe+.â??

Officials attributed the spike to a western disturbance, unfavorable meteorological conditions, and the lack of pollutant dispersal.

In its notification, the CAQM Sub-Committee said the decision to invoke Stage-IV was taken unanimously as a proactive step to prevent further deterioration.

Under GRAP, air quality is classified into four stages: Poor (201â??300), Very Poor (301â??400), Severe (401â??450), and Severe+ (above 450).

Stage-IV restrictions, first introduced in December 2025, include a ban on vehicles entering Delhi that are not BS-VI compliant and do not carry Delhi registration.

Non-essential trucks are barred from entry, with exceptions for those carrying essential goods or running on cleaner fuels such as CNG, LNG, electric, or BS-VI diesel.

Construction and demolition activities, including public infrastructure projects like highways, flyovers, and pipelines, are completely halted.

To protect vulnerable groups, state governments in NCR and the Delhi administration may shift classes VI to IX and XI to online mode, while Classes X and XII are generally exempted to avoid disruption to board exam preparations.

Officesâ??public, municipal, and privateâ??are advised to operate with at least 50 per cent staff working from home, and staggered timings may be introduced to ease peak-hour traffic.

Authorities also retain the option of discretionary emergency measures, such as closing colleges, suspending non-essential commercial activities, or implementing odd-even vehicle rationing schemes.

The central government may extend work-from-home directives to its employees if conditions worsen further.

With Delhiâ??s AQI inching closer to the â??Severe+â?? mark, the reimposition of GRAP-4 reflects the urgency of tackling the capitalâ??s recurring pollution crisis, which continues to pose grave risks to public health and daily life.

/IANS