Officials said the fire broke out on the first floor, which was the most effected. The loss of property is being estimated at several crores, officials said.

The fire broke our around 12.45 am in the cargo floor located adjacent to the Air Traffic Control (ATC) building which has nearly 20 international airline offices, including Air India and Air Sri Lanka.

Deputy Commissioner of Police (Airport) R A Sanjeev said, “The fire was reported between 12:45 am and 1 am. No one was injured in the incident and the cargo is intact.”

Sources said the night staff noticed the flames and informed officials at the airport. Eyewitnesses have told police the fire started at the Thai Airways office; details of which are yet to be verified.

A K Sharma, Delhi Fire Services (DFS) chief said, “Twenty eight fire tenders were rushed to the spot. The cause of the fire is yet to be ascertained”.

Officials do not rule out the possibility of a short-circuit. “The fire department will prepare a final report which will take some time” an official said.

Airport staff said fire tenders managed to douse the flames in nearly five hours. “The fire was brought under control around 6 am” an official said.

There was some delay in informing the fire department as the airport's night staff first tried a hand at it with the extinguishers in the premises. By the time they realised the fire was going out of control, a little over half an hour had been lost in informing firefighters. They were finally called in at 1.15 am. Add to this the dense fog at night and the team was further delayed from reaching the airport.