
The incident occurred around 8:30 pm at Tetulia village under Rajpat union of the upazila.
The deceased were identified as Rahela Begum, 50, wife of Mosarraf Shikder of Tetulia village, her grandson Saifan Shikder, 8, son of Sajib Shikder, and neighbour Iran Shikder, 55, son of Hafiz Shikder.
Officer-in-Charge of Kashiani Police Station Mohammad Mahfuzur Rahman said an electric wire had been set up beside the house of Sajib Shikder to protect Boro rice seedlings from rats.
Saifan first came into contact with the live wire and was electrocuted. As Rahela Begum rushed to rescue him, she was also electrocuted and died on the spot.
Neighbour Iran Shikder later attempted to save them and was likewise electrocuted, dying at the scene.
Saifan was taken to Muksedpur Upazila Health Complex in a critical condition, where the on-duty physician declared him dead, reports BSS.
Police of Kashiani Police Station visited the spot and prepared an inquest report. Legal proceedings are underway, the police official added.