At least 14 Air India flights have been cancelled as a strike by the pilots of India's national carrier entered its seventh day.
Thousands of passengers have been stranded at Delhi and Mumbai airports. Many have complained of a lack of information from the airline.
The airline has sacked more than 70 pilots over the past few days in a dispute over training.
India's aviation minister renewed his call for pilots to enter talks.
Officials said at least eight Air India international flights and six domestic fights were cancelled overnight on Sunday.
Reports said about 200 pilots have called in sick since last Tuesday amid a dispute over training for the new Boeing 787 Dreamliner planes.
The pilots are protesting against the decision to train pilots from Indian Airlines, which merged with Air India in 2007, to fly the new planes.
Air India pilots say that as the planes were ordered before the merger, they should be given priority for training.
A day after the action began, the Delhi High Court ruled that the pilots' strike was "illegal" and ordered them back to work, but many pilots have refused to return to duty.
The airline last week said it had stopped taking bookings for US and Europe-bound flights until 15 May.