Noida, Dec. 15 -- The Gautam Budh Nagar, and Ghaziabad district administrations on Sunday ordered online classes for pre-nursery to Class 5, and hybrid mode for Classes 6 to 12, a day after the Graded Response Action Plan (Grap) Stage-4 was invoked across the Delhi-NCR as air quality plunged into "severe" category. "As directed under Grap-4, all schools affiliated with various boards in Gautam Budh Nagar will shift to online mode from pre-nursery/nursery to Class 5 and hybrid mode-both online and physical (wherever online mode is feasible)-for Classes 6 to 12," said Rajesh Kumar Singh, district inspector of schools, GB Nagar, in a statement. "All principals and headmasters of government, aided, and private schools, as well as coaching centres , have been instructed to ensure strict compliance. Other authorities have also been directed to monitor effective implementation. Similarly, the Ghaziabad administration also issued comparable directions for schools. As per the CBCB's 4pm data, in GB Nagar, Noida recorded an AQI of 466, up from 455 on Saturday while Greater Noida logged 435, slightly better from 442. Ghaziabad district saw sharp rise on Sunday to 459 from 430 a day earlier.Arun Singh...