Tirupati, March 20 (IANS): Four helicopters of the Indian Air Force (IAF) and 100 army personnel Thursday joined an operation to douse a fire raging in Seshachalam forests for three days, officials said.

Two Mi-17 and two C130 helicopters took off from Renigunta airport near Tirupati in the afternoon to put out the fire, which is reported to be raging about three km from the famous Balaji temple atop Tirumala Hills.

Making several sorties over the forests, the choppers tried to put out the fire by spraying water and chemicals.

Earlier, Sambasiva Rao, director general, fire services, made an aerial survey of the forests.

Tirumala Tirupati Devasthanam (TTD), which manages the affairs of the famed temple, said the flames at Kakula Konda near Tirumala were controlled to a large extent but the fire was still raging in Papavinasanam.

"We are not taking any chances as this is summer season. The operation will continue till the fire is completely extinguished," said TTD joint executive officer K. Srinivasa Raju.

The choppers and army personnel joined hundreds of civilians battling the fire, which has already destroyed over 5,000 hectares of forest.

TTD has closed both the pedestrian pathways leading to Tirumala Hills as a precautionary measure. It has mobilized more than 1,000 personnel from forests, fire services, police and other departments to control the fire.

The authorities reportedly failed to take timely action, which resulted in the fire spreading to a vast area. A small fire was first spotted in the forest range a week ago. The forest department allegedly did not act on the alerts from the National Remote Sensing Centre (NRSC) and the National Aeronautics and Space Administration (NASA) of the US.

As Tirumala Hills is a no-fly zone, TTD had to consult the priests, before granting permission to deploy helicopters. This delay also reportedly led to the fire spreading to new areas.