More than 5,000 Armymen were called in to help control the Bellandur lake fire in Bengaluru on Friday. It took them and firefighters over seven hours to control the blaze.

The 1,000 acre expanse of the Bellandur lake is infamous for severe pollution and froth that spills over and catches fire. Friday’s blaze was the first time it caught fire in 2018. Huge plumes of smoke could be seen billowing over the lake even from a distance.

The flames were doused on Friday evening, but started again later in the evening in two places. A jet fighter engine that can throw water up to 300 metres was sent to the city’s largest lake.

The joint commissioner of the Bruhat Bengaluru Mahanagara Palike (Mahadevapura zone), Dr Vasanti Kumara, said grass in the area had powered the flames. Firemen at the lake said the situation was “extremely grim”. “The wind is changing directions, too, but there is no reason to panic,” they added.

This is the fourth time since 2015 that the lake caught fire. The city’s two largest lakes – Bellandur and Varthur – are regularly affected by froth. Environmentalists blame the practice of dumping untreated sewage and pollutants in the lakes for the severe pollution.

Residents from the area have asked the government time and again to take action to stop the lake from foaming. Many have also criticised the civic bodies for failing to address the problem