NEW DELHI, Nov. 18 (Xinhua) -- The strictest anti-air pollution measures under the Graded Response Action Plan-4 (GRAP-4) were invoked in Delhi and nearby areas on Monday as air quality turned severe over the past several days.
At several places in the national capital and surrounding areas, the Air Quality Index (AQI) touched 500 on Monday, which was described as "severe" according to the System of Air Quality Forecasting and Research (SAFAR) norms.
The GRAP-4 measures included banning of trucks' entry into Delhi except for the ones carrying essential commodities or providing essential services.
As precautionary measures, primary and middle schools were shut in Delhi and other areas, and office timings were staggered to reduce the number of cars on roads to curb vehicular pollution.
Meanwhile, 14 Delhi-bound flights were diverted to other cities, including Jaipur and Dehradun, due to poor visibility. ■