Officials cordoned off the area soon after the incident was brought to their notice, airport sources said.
Arrangements have been made to replace the glass, they said.
This is the latest in a series of such incidents of collapse of false ceiling, glass doors and panels and granite slabs at the new domestic and international terminals of the airport, built at a cost of over Rs 2,000 crore and inaugurated by Vice-President Hamid Ansari in January 2013.
Today's incident is the third since the last month end. On March 31, a sensor glass gate collapsed at the terminal, injuring an employee of the airport while a big glass door came crashing down, causing panic among passengers and security personnel about a week later.