It occurred when lightning struck a pole balancing wire tied to an adjacent post in a pond and killed all the fish in it.

Eight-year-old Naim got into the pond for the dead fish and was electrocuted. Seeing her son in distress, Nasima Akhtar, 28, rushed into the pond to save the boy and she, too, was electrocuted.

Nasima's brothers, Shahidullah, 35, and Shafiqul Islam, 22, were also electrocuted as they jumped into the pond to rescue their sister and nephew.

Nasima lived at her father's house with her two sons and a daughter.

Locals organised a rally to protest Desa's neglect, which, they said, led to the deaths. They complained that Desa did nothing to eliminate the source of danger, and they were forced to tie the pole balancing wire to a post in the pond. Police have been deployed in the area.

Speaking on the incident, Desa Executive Engineer Aminur Rahman said, "We are deeply shocked at the deaths, and a probe is on to find out the cause behind the accident."

The investigators are looking into any illegal redirection of electric wires from the pole that might have led to the accident, Desa sources said.