Kathmandu, Sept. 26 -- Anyone flying out of Kathmandu's Tribhuvan International Airport on an Indian-registered aircraft undergoes an additional security screening just before boarding. At a screening point on a raised platform on the airport apron, staffed by Indian security personnel, passengers are frisked, and their luggage is subjected to a thorough hand search. It's hardly a secret; nor is it new. But after more than a quarter of a century, it is simply part of boarding.

An official at the Civil Aviation Authority of Nepal said Air India and IndiGo both deploy Indian staff at Tribhuvan in three shifts. Of the 12 to 15 people working a single flight, six to eight are Indian employees stationed on the apron. They wear the heavy boots...