India, Sept. 22 -- The immigration lapse involving three Italian passengers who travelled from Amritsar to Munich via Delhi without obtaining mandatory departure immigration clearance on September 4 has prompted an interim security measure at Delhi airport.

Multiple officials aware of the matter said that additional checks are being carried out at transfer points to verify the nature of a passenger's onward journey and ensure that those required to undergo immigration do not bypass the process.

"As part of the interim arrangement, airline staff have been directed to pay closer attention to the 'I' and 'D' indicators on boarding passes of transfer passengers," one of the officials said.

The markings indicate whether a passenger is trave...