India, Dec. 27 -- Even as Graded Response Action Plan (GRAP) 4 restrictions were lifted after a temporary improvement in air quality, Delhi Environment Minister Manjinder Singh Sirsa on Friday urged residents to continue following pollution-control measures, warning that weather conditions may worsen again due to an approaching western disturbance.

Meanwhile, the Delhi Transport Department (DTC) has intensified its anti-pollution enforcement drive under the GRAP restrictions, impounding 28 buses, including interstate vehicles, in a day for violating emission norms. Enforcement agencies inspected 4,927 vehicles across the city in the past 24 hours and issued 3,970 challans. Of these, 2,390 challans were issued by the Delhi Traffic Police ...