India on Tuesday cancelled all flights to Kathmandu after Nepal plunged into a political crisis following the sacking of the Sher Bahadur Deuba government by King Gyanendra.

Also see: Emergency imposed in Nepal

An Air Sahara flight took off from Delhi in the morning but returned after hovering over Kathmandu airport. It was not permitted to land by the local air traffic control.

Indian Airlines and Jet Airways [Get Quote] cancelled their flights to Kathmandu.

Also see: India voices concern

IA sources said they were on "stand-by" as the airline's Kathmandu office had not given clearance to its flight till afternoon.