"Major fire that was there yesterday has been doused, but there is still smoke emerging in some small pockets," a senior fire department official said.
He said they were now trying to ensure that the embers from which the smoke emanated do not reignite due to wind.
Water from the lake was used to put off the fire, the cause of which would be known after investigations, officials said.
The blaze started Friday in the highly-polluted and biggest water body of the city, giving anxious moments to hundreds of residents living nearby before it was doused last night.
It had also spread towards the nearby Iblur firing range of the Army, the officials said.
The army said the fire, which had spread to the perimeter of its facility, had been doused due to the untiring efforts of more than 5,000 of its personnel and fire fighting equipment of the Army Service Corps (ASC) Centre and College.
Lt Gen Vipin Gupta, commandant ASC Centre and College, said Saturday that things were under control.
As voices were emerging that the fire may have started due to a methane burst as a result of accumulation of chemicals and pollutants in the lake, authorities also suspect the involvement of local grass harvesters in starting it.
Fire department officials said the reason behind the fire has not yet been determined and their priority was to put off the fire completely. "Later, investigation will be done to know the cause of fire," a senior official said.
"We have a lot of fire tenders there and we are ready for any eventuality," he said.
Lt. Gen. Gupta said this was the first time the blaze had spread to their camp. "It had never interfered with our activities, but now that it has come very close to us we will definitely take up the case with civil authorities," he said.
Asked if the Army will take up the lake's cleaning, he said they were always ready to help the civil administration.
But as far as cleaning was concerned "it is a very technical and professional job" for which people were available on the civil side, he added.
Spread over 1,000 acres near the infotech hub, the lake is highly contaminated as it receives 60 per cent of the sewage generated in the city. It is in a bad shape despite the National Green Tribunal pulling up the government and its various agencies for failing to prevent pollution and not doing enough to restore the lake.
The Bellandur lake had caught fire in May 2015 and August 2016 as well.
In 2015, the lake had turned into a frothy, foam-filled water body due to high concentration of pollutants in the waters. Foam from the lake spilling onto nearby roads and surrounding areas had become a common sight everytime the city received heavy rainfall.
The nearby Varthur lake was also in the focus when it caught fire in May 2017.