People are dying from extreme heat, which is also killing a large number of chickens and destroying tea plants
The three girls, 'Moriom', 8, 'Salma, 5, and Salma's sister 'Laboni', 4, went to bathe in the river with other members of their families on Friday afternoon, Kumarkhali Police Station OC Abdul Khaleq said.
They drowned at one stage of bathing at village Chardasipur, and their bodies floated after around an hour. The locals pulled up the bodies.
Moriom is the daughter of Shafi Uddin, a resident of Sheikhparha village.
Her cousins Salma and Laboni were on a visit to Moriom's house, the police officer said, quoting their relatives.