The deceased were identified as Sharda Rathva and her two sons Kaushik (5) and Ankit (9), Thasra police sub-inspector of Thasra V G Prajapati.
He said that preliminary investigation revealed that in a bid to save Kaushik from drowning, his elder brother Ankit and their mother Sharda too drowned in the pond.
The incident happened in the afternoon when Sharda, accompnied by her two sons, was working on a farm and Kaushik went to a nearby farm pond to fetch water, Prajapati said.
When both of them began shouting, Sharda jumped into the water to save her sons, Prajapati said.
"However, she and her two sons failed to come out and eventually drowned to death. Later, villagers rushed to the spot and fished out their bodies. We have registered a complaint of accidental death and started an investigation," Prajapati said.