"All our long-haul flights to the U.S., Europe, Riyadh and Jeddah have been cancelled. This has been done due to non- availability of pilots who are on mass sick leave since Tuesday," an Air India official told the media.

A worried Civil Aviation Minister Ajit Singh met the Prime Minister this morning and briefed him on the stand-off.

"I updated the PM on latest developments. Whatever we are doing is according to government policy. He has asked me to ensure that fares should not be increased because of these strikes," the Minister told the media.

The Delhi High Court on Wednesday termed the strike as illegal. But the Supreme Court refused to hear a lawsuit the airline's management filed against the pilots over contempt of court. Instead, it advised the national carrier to talk with pilots and sort differences out.

"I am not aware of what the Supreme Court has said. But we have always been willing to talk. However, we maintain that there is no need for the pilots to undertake an illegal strike," Singh said when asked about the top court's position.

Some 250 pilots of Air India have been on mass sick leave over promotion and rescheduling of training for the carrier's new Boeing dreamliner, which is meant to join the national carrier's fleet later this month.

The Air India management has sacked at least 46 pilots in the last three days for not reporting for duty. But despite the the extreme action, pilots remain defiant.

In 2007, Air India merged with Indian Airlines, the state-owned domestic carrier. Since then, pilots from the two airlines have clashed repeatedly over issues like parity in pay and seniority.