Thousands of Air India passengers have been stranded after a strike by staff in protest at an alleged ban on them speaking about Saturday's air crash.
At least 158 people died in the Air India Express disaster in Mangalore.
Reports say about 100 domestic and international Air India flights have been cancelled after 20,000 ground staff walked out.
Unions say management is banning staff from talking to the media about the crash, a charge the airline denies.
Soon after the accident, some Air India employees alleged that the airline was flouting safety regulations, something the airline also denies.
Flights cancelled on Wednesday include ones from Mumbai (Bombay), Delhi, Calcutta and Bangalore as well as international destinations such as Kathmandu, Singapore, Bangkok and Dubai, reports say.
Talks are expected to be held between the unions and the airline management and the Indian cabinet is also discussing the issue.
Federal aviation minister Praful Patel has called the strike "irresponsible".
'Not going to buckle'
State-run Air India has appealed to its workers to call off their strike, saying it has a "well-established system of dealing with any grievance".
It said a section of employees had "misinterpreted" an office order issued last year which advises them to "desist from going public with their statements that have the potential of harming the company's revenue earning prospects".
"Any employee violating these norms will render himself liable for disciplinary action," the office order, issued in July 2009, states.
But Union leader Vivek Rao told the AFP news agency the strike would continue.
"We are not going to buckle under pressure... We are asking for the gag order to be removed."
Correspondents say the latest strike action is evidence of the troubles afflicting the loss-ridden airline and friction between management and employees belonging to a dozen unions.
The leader of one of the striking unions, JB Kadian, told the Press Trust of India news agency that another aim of the strike was to "protest the delay in payment of salaries and highlight the problems of the cabin crew".
But not all union leaders back the strike. One head of a crew union said it was poorly timed.
"At a time when we are mourning the death of our colleagues and passengers, it's grossly incorrect," Sanjay Lazar said.
"It's a time for us to heal and move forward. All the bodies have not yet been identified."
Aviation analyst Kapil Kaul said the strike, days after one of the worst accidents in the company's history, "reflects no concern for the organisation".
"It is a wake-up call for the government - the situation is so deep that their continuing inaction could be fatal for the company," Mr Kaul said.
He said that the government had given a $168m (£117m) bailout to the ailing airline and promised $252m (£175m) more.
Analysts say the airline's 30,000 workforce needs to be cut by half to make it competitive. Air India has a fleet of 136 aircraft flying to domestic and international destinations.
Investigators are still trying to find out why the Air India Express Boeing-737 crashed at Mangalore airport.