Air India and IndiGo are among the airlines that cancelled flights connecting Kathmandu on Tuesday, after the Tribhuvan International Airport in Nepal’s capital was temporarily closed due to massive anti-government protests, news agency PTI. Nepal Airlines also called off its Delhi-Kathmandu flight.

According to a PTI source, an Air India flight returning from Kathmandu had to turn back to Delhi after smoke was noticed at the airport during its final approach. Another Air India flight bound for Kathmandu from Delhi was diverted to Lucknow before returning to the national capital.