NEW DELHI - Air India Express said on Thursday its cabin crew has rejoined work after reporting sick this week, ending disruptions in services at the Tata Group's budget carrier that cancelled its flights for the second day.

"We sincerely apologise to those inconvenienced by these unintended disruptions. It is not in keeping with our usual service standards, and we will review it internally to ensure accountability," Air India Express spokesperson told Reuters late on Thursday.

Air India Express has cancelled at least 175 flights in the past two days and several others delayed after more than 100 cabin crew took sudden sick leave on Tuesday night.

Out of over 360 daily flights, Air India Express said it has cancelled 85 on Thursday with over 90 impacted a day prior.

The budget carrier operated 283 flights on Thursday with the support of Air India on 20 routes, it had said earlier in the day.

Air India was bought by salt-to-software conglomerate Tatas in 2022. Under the new structure, the airline is being merged with Vistara, while Air India Express merges with AirAsia India.

The disruptions are the latest setback to India's aviation market after Vistara was forced to scale back 25-30 flights a day because of a pilot shortage in April.

Air India Express said it was "taking appropriate steps" against some employees, referring to those cabin crew who reported sick at the last minute.

The airline, which employs over 2,000 cabin crew, flies to 31 domestic and 14 international destinations and has a fleet of over 70 aircraft.

Chief Executive Aloke Singh has said the disruptions "cascaded across the network", forcing the company to curtail the schedule over the next few days.

(Reporting by Tanvi Mehta in New Delhi and Nandan Mandayam in Bengaluru; Additional reporting by Urvi Dugar in Bengaluru; Editing by YP Rajesh, Susan Fenton and Shilpi Majumdar)