A mysterious fire gutted over 10 acres of woods at the Turahalli reserve forest close to the city on Sunday.
Local residents joined hands with forest officials to put out the leaping flames two hours after it was first spotted around 2 pm.
Officials said this is the first forest fire inside the reserve this year, though sporadic incidents of garbage being set on fire had been reported.
Forest officials have been struggling to safeguard the sprawling 60-acre wooded patch closest to the city against the locals, villagers, property developers, politicians and other influential people interested in either encroaching the place or clearing it for development.
Sunil Baberwal, member of Eco Volunteers India Trust and resident of an apartment complex on the fringes of the forest, said the residents rushed immediately to the officials' aid to douse the fire.
"Miscreants wanting to encroach upon the forest have done this," he said.
People used to enter the woods to drink or do drugs, but such illegal activities had been brought under control, Baberwal added.
Officials have also asked the locals to be on the vigil and report any untoward incidents occurring in the woods.
They should also help the forest department put out forest fires and provide water and other materials for the purpose.