A case has been registered and two persons have been arrested in connection with the attack, police said.
As the BSES team checked meters in some houses and detected power theft, a mob gathered and protested aggressively, they said.
"Three BSES employees and sub-inspector Parveen Kumar posted at Ranhola police station were injured during the attack. The SI was hit on his head. Two accused Hari Prakash Lakra and Jogender Lakra have been arrested while other accused are absconding," said the officer.
A BSES spokesperson said it was not an isolated incident.
Despite intensive efforts to reduce power theft, Ranhola, a village in Mundka division, continues to record massive losses of around 40 per cent, the BSES spokesperson said.
In the last two years, around 450 cases of power theft having a connected load of around 1,200 KW have been recorded in the area, he added.