With Air India pilots not budging from their position, their agitation entered the sixth day on Sunday leading to cancellation of 20 international flights, causing inconvenience to the hundreds of passengers.
"Pilots have not reported for work. We have had to cancel 20 flights from Delhi and Mumbai," an Air India official said.
Hundreds of passengers were stranded following the flight cancellations.
The passengers alleged they had not been given the refund by the airline against their booked tickets after the cancellation of the flights.
The airline management has sacked 71 pilots and also sought cancellation of the flying licenses of 11 office- bearers of the Indian Pilots' Guild (IPG), which is spearheading the agitation.
DGCA on Saturday issued show-cause notices to 11 pilots of the IPG after the airline management sought cancellation of their flying licences.
Over 200 pilots owing allegience to IPG are on strike since Tuesday, badly disrupting the international operations of the national carrier.
The airline has also suspended its bookings for international flights till May 15.
Union Civil Aviation Minister Ajit Singh has asked the pilots to consider the plight of passengers and said, "We are ready for talks but they must call off their strike".
"The first priority must be to make sure that the passengers feel they are being listened to. So let the pilots decide that. Ask for forgiveness from passengers. Start the flights ... we can talk on anything after that," Singh has said.