Air travel across India has been in turmoil this week after IndiGo cancelled thousands of flights, prompting the government to announce special relief for the carrier and operate some trains to help clear the backlog.

It is the biggest crisis ever for the 20-year-old airline, which long prided itself on on-time performance and lured passengers with low-cost fares.

IndiGo has admitted it failed to plan properly ahead of a November 1 deadline to implement stricter rules for pilots around night flying and weekly rest, which ultimately led to problems around roster planning this week.

On Friday, more than 1,000 IndiGo flights were cancelled. The Delhi airport in a post on X said flight operations are steadily resuming, but some IndiGo flights continue to be affected.

Airport sources told Reuters 124 IndiGo flights in Bengaluru have been cancelled on Saturday, 109 in Mumbai, 86 in New Delhi and 66 in Hyderabad.

India’s government has made special relaxations to the rules for the airline, and IndiGo has said it could return to normalcy between December 10-15.

Still, hundreds of passengers gathered outside Bengaluru and Mumbai airports on Saturday, with some clueless about their cancellations, according to Reuters photographers present at the scene.

Satish Konde had to catch a connecting flight to go to the western city of Nagpur from Mumbai, and was checked in, but was told later that it was cancelled.

“I am waiting for my luggage to be returned,” he told Reuters at the airport.

Other major Indian airlines, including Air India and Akasa, have not had to cancel flights due to the new rules.