India, Dec. 14 -- As Delhi reels under severely toxic air quality, the government has enforced Stage 4 of the Graded Response Action Plan (GRAP) in urgent efforts to curb the deteriorating air quality in the region.

With the restrictions kicking in, Delhi schools have not been shut completely, but classes have moved to a hybrid format for several grades.

According to a circular issued by the Delhi Directorate of Education (DDE), schools have been directed to conduct classes in a hybrid format - both physical and online options - for certain grades, wherever online teaching is feasible.

The circular, dated December 13, states: "All Heads of Schools of Government, Government Aided, Unaided Recognized Private Schools of DOE, NDMC, MCD, an...