Air India Ltd.’s low-cost airline has canceled more than two dozen additional flights, and expects disruptions to continue for days, after cabin crew called in sick en masse.

More than 100 cabin crew reported sick prior to their rostered flight duty at the last-minute, throwing more than 90 flights into disarray, Air India Express Chief Executive Officer Aloke Singh wrote in an internal memo to employees that was seen by Bloomberg News.

“The disruptions have cascaded across the network, forcing us to curtail the schedules over the next few days,” it said. 

The airline fired at least 25 cabin crew for taking sick leave between Tuesday and Wednesday, local media outlet ANI reported, citing people it didn’t identify. 

Air India Express canceled 85 flights Thursday, it said in a statement. Parent Air India will offer services on 20 of its budget unit’s routes to mitigate the travel disruptions, it added. 

The carrier is engaging with cabin crew to address their concerns and taking “appropriate steps against certain individuals as their actions have caused grave inconvenience to thousands of our guests,” according to the statement.

The airline said Wednesday that it’s trying to find out the reasons for the absences, though Singh’s memo urged workers to embrace change and transformation. The carrier is currently integrating with AirAsia India as part of its aggressive expansion plans.

Air India Express’ difficulties are just the latest in a series of disruptions centered on Tata Group’s aviation business, which is in the midst a revamp after the conglomerate bought Air India from the government in 2021. 

The widespread absenteeism echoes the experience at Vistara, the Singapore Airlines Ltd. local affiliate that’s expected to merge with Air India by the end of the year. Pilots there also called in sick en masse over fatigue concerns and pay cuts, forcing the airline to cancel more than 100 flights over the course of a week and eventually scale back its schedule to prevent further cancellations. 

If a flight is canceled or delayed for more than three hours, customers can opt for a full refund or reschedule, Air India Express said in a statement Thursday. India’s Ministry of Civil Aviation has also weighed in, urging the carrier to resolve issues promptly and submit a report on the flight cancellations.