Chief Justice Sanjiv Khanna on Tuesday said all judges have been asked to allow virtual hearings wherever possible in view of the severe pollution levels in the national capital region.

Efforts to control the escalating crisis have included the enforcement of Phase 4 of the Graded Response Action Plan (GRAP), but the situation remains grim as cold weather and stagnant winds trap pollutants over the region.

India's capital city of Delhi has virtually shut down as air pollution hit "severe plus" levels, according to Indian government officials in its pollution control authority.