A major glitch at Delhi's Indira Gandhi Airport resulted in flight numbers and boarding passes being written out by hand.
Electronic terminals at the airport have stopped working.
Due to a global IT problem, a number of services at the airport were temporarily unavailable, the airport said in a message posted on its personal blog.
Passengers also reported being given boarding passes and baggage tags that were filled out by hand.
Flight number information was noted on the office board with a marker.
Similar failures were observed at airports in the USA, Great Britain, Portugal, and the Netherlands.
The cause of the failure was an update to the Crowdstrike antivirus program, which affected Microsoft operations worldwide.
