The fire was caused due to malfunctioning of batteries, Airport Director H S Suresh said, adding, a probe has been ordered into the incident.
A total of 12 incoming and outgoing flights were affected even as flights arriving in the city were diverted to other locations including Bangalore and outgoing services resumed around 6 AM, sources said.
The overall operations had become normal around 8 AM though some flights were delayed due to the mishap which occurred around 2.40 AM, airport sources said.
No casualty was reported but computers and the ceiling in the ATC hall was damaged in the fire, sources said.
Meanwhile a car went up in flames in the airport premises after the driver lost control of the vehicle and dashed it against the wall, airport sources said.
The driver fled from the spot.