Air India announced the cancellation of four international flights today from Mumbai and Delhi, as the agitation by a section of pilots entered the second day today.

Around 200 pilots of the pilots owing allegiance to Indian Pilots Guild (IPG) had reported ''sick'' by the end of Tuesday, as the protest launched on Monday snowballed despite warnings of stern action by the management and the government.

"Four flights have been cancelled today, two each from Delhi and Mumbai," Air India spokesperson said in Mumbai. All other international flights are operating, as a contingency plan has been put in place with the available pilots, he said.

The Air India management had on Tuesday terminated the services of 10 office-bearers of the IPG, which is spearheading the strike, besides de-recognising the guild.

The IPG represents pilots who were with Air India before Indian Airlines was merged into it.

"The management is also mulling the option of approaching the court against the pilots' agitation," airline sources said, according to PTI.

Passengers were the worst sufferers. Many were seen having heated exchanges with the airline staff in Delhi. They said the staff was uncooperative and not providing any information about their flight or any alternate flights.

Some of the stranded passengers, who had checked in their luggage and also got their boarding passes, had to wait for hours to get back their luggage.

Terming the agitation by the pilots as "illegal", civil aviation minister Ajit Singh had said on Tuesday that the pilots should consider what the result of their action would be.

"The government is trying to bail out [the ailing airline] and giving lot of money. But part of that bailout is with conditions that they have to perform. For the last three months Air India was doing better. Now with this action, they should consider what the result would be," he said.

He told the striking pilots that they should first decide what they want – either keep the national carrier afloat or shut it down.

"We cannot keep pouring money to keep Air India afloat," Singh said.

The latest casus belli is the management's decision to send pilots from the erstwhile Indian Airlines, which merged into Air India in 2007, for training on the Boeing 787 Dreamliner, the near-bankrupt airline's latest purchase. The decision was upheld by the Supreme Court, despite which heartburn continues among the IPG pilots.

Indian Airlines pilots, mostly trained to fly domestic routes, have long been clamouring for parity in pay and training with IA pilots; and the move to send them for Dreamliner training seemed an appropriate step in this direction. However, it has raised a hornets' nest.'

Air India pilots have said the planes were ordered before the merger, so they should be preferred for training.