The dead have been identified as Phulbashi Chandra Das, 34, and her daughter Sumi Chandra Das, 12.
A preliminary investigation suggests they have been strangled to death, police said.
Phulbashi’s husband Mukundra Chandra Das, 36, and her elder daughter Jhuma Rani Das, 14, have been detained for questioning over the incident.
Informed by locals, police recovered the bodies from a house in Nayagaon’s Goli No. 3, Kamrangirchar Police Inspector (Investigation) Mostafa Anwar said.
“The victims have cuts on their necks.”
Mukunda, a vegetable trader, also works as a driver. He has been living in a rented room of a tin-roofed house with his family.
He is believed to have killed his younger daughter Sumi by wrapping polythene around her face, police said, citing the victim’s elder sister Jhuma.
Police are interrogating both Mukunda and Jhuma to unravel the actual motive behind the incident.