Air India Express on Thursday cancelled 85 flights or around 23 per cent of the total daily capacity as the disruptions due to the cabin crew shortage continue and said Air India will operate services on 20 of its routes to minimise inconvenience to passengers.

In a significant decision, sources said Air India has issued termination letters to around 25 cabin crew members who reported sick to protest against alleged mismanagement at the airline that forced it to cancel more than 100 flights since Tuesday night.

Without directly mentioning about the termination letters, the airline said it is taking appropriate steps against certain individuals as their actions have caused grave inconvenience to thousands of passengers.

"We will be operating 283 flights today. We have mobilised all resources and Air India will support us by operating on 20 of our routes. However, 85 of our flights stand cancelled," the airline said in a revised statement on Thursday.

The cancellations account for around 23 per cent of the Tata Group-owned airline's scheduled daily flights of about 368. In the earlier statement, the airline said it has cancelled 74 flights and will be operating 292 services.

The carrier has asked passengers to check if their flight is affected by the disruption before heading to the airport. If the flight is cancelled, or delayed beyond three hours, they may opt for a full refund or reschedule to a later date without any fees, it added.

Earlier in the day, sources said the airline has issued termination notices to 25 cabin crew members who had reported sick and asked others to join back for duty by 4 pm on Thursday.

Against this backdrop, Air India Express said it is taking appropriate steps against certain individuals.

"While we will continue to engage with our cabin crew colleagues with a commitment to address any concern, we are taking appropriate steps against certain individuals as their actions have caused grave inconvenience to thousands of our guests," it added.

On Wednesday, the civil aviation ministry sought a report from Air India Express on the cancellation of flights and also asked the airline to resolve the issues promptly.

Discontent has been brewing among a section of staff at Air India Express since the start of the process to merge AIX Connect, formerly AirAsia India, with itself.