New Delhi, Nov 5 : The Commission for Air Quality Management (CAQM) on Sunday decided to invoke Stage IV of the Graded Response Action Plan (GRAP) in the entire Delhi-NCR with immediate effect, banning entry of trucks and switching over to work from home, to prevent further deterioration of air quality in the national capital. GRAP are set of measures drafted by the Centre's CAQM to tackle air pollution. The Stage IV is the highest level of pollution alert. The 8-point action plan as per Stage-IV of GRAP is applicable with immediate effect from Sunday in the entire NCR. Under it, entry of trucks into Delhi is banned. However, those carrying essential commodities/providing essential services and all LNG/CNG/electric trucks will be allowed. There will also be a ban on the plying of Delhi-registered, diesel-operated Medium Goods Vehicles (MGVs) and Heavy Goods Vehicles (HGVs) in Delhi, except those carrying essential commodities/providing essential services. The state government may take a decision on discontinuing physical classes even for classes 6 to 9, 11 and conducting lessons in an online mode. Delhi, NCR state governments can also ask public, municipal and private offices to work on 50 per cent strength and the rest to work from home. The state governments may consider additional emergency measures like closure of colleges/educational institutions, closure of non-emergency and commercial activities, permitting running of vehicles on odd-even basis of registration numbers etc. /IANS