New Delhi, April 24 -- Indian carriers' international flights plunged to a four-year low in March, as Iran's retaliatory strikes across the Gulf disrupted key aviation routes following US and Israeli attacks, triggering widespread airspace closures and flight cancellations.

International departures by Indian airlines fell 40% year-on-year to 11,284 flights in March from 18,502 a year earlier, according to data from the Directorate General of Civil Aviation (DGCA). Passenger traffic dropped more than 36% over this period, with 1.84 million passengers flying overseas, compared with 2.9 million in March last year.

Air India Express was the worst-hit among local carriers. The low-cost carrier of the Air India Group, which has a heavy exposu...