India's biggest airline IndiGo faced a growing crisis, with more than 300 flights cancelled since Tuesday, leaving thousands of passengers stranded nationwide.

Delhi, Mumbai, Hyderabad and Bengaluru - among India's busiest airports - were worst hit.

The airline blamed technical glitches, weather and new crew rostering rules for the disruption.

The budget airline, with over 60% domestic market share, links major metros and smaller cities.

IndiGo said it had made "calibrated adjustments" to its schedule until Friday to stabilise operations.

On Thursday morning, ANI news agency reported 33 IndiGo flight cancellations at Delhi, 85 at Mumbai and 73 at Bengaluru.

Videos of frustrated flyers circulated on social media and many passengers took to X (formerly Twitter) to complain.

Most complaints on X received the airline's standard response: "Our operations are dependent on several factors, some of which are beyond our control and may impact the schedule."

India's aviation regulator is reportedly investigating the disruptions and has asked the airline to explain the reasons behind the cancellations and delays.

Since 1 November, IndiGo has faced pilot and crew shortages under new Flight Duty Time Limit (FDTL) rules, which limit flight hours and mandate more rest, media reports say.

However, the Federation of Indian Pilots said the cancellations "cannot be attributed" to the new rules, noting other airlines remain largely unaffected.

The BBC has reached out to IndiGo for a comment.

This crisis hits the reputation of the two-decade-old carrier, which built its brand on punctuality. However, in recent months its performance has slipped.

According to a recent survey by online community platform LocalCircles, 54% of the airline's passengers reported issues with its timeliness over the past year.