The officials at the Chennai airport swung into alert mode after a bomb threat call was made on Friday.
The timing of the threat was also crucial in that it was hours before the arrival of the vice president and defence minister to the Tamil Nadu capital.
The call was made to an airline operating flights between here and Hyderabad and security measures have been put in place.
Twenty flights are scheduled through the day between the two cities.
Security was stepped up at the airport in view of Vice President Venkaiah Naidu and Defence Minister Nirmala Sitharaman visit.