Sunil (6), Chote (5) and Reena (4) died after they had tea in which pesticides were mistakingly mixed in place of tea leaves, police said.
Two more children of the family were also taken ill and were rushed to a hospital.
On April 28, a 3-year-old boy had died and five members of his family were taken ill after consuming toxic tea in Bhimnagar district of the state.
