A couple and their two minor children were found with their throats slit at their home at Binnakandi village in Goainghat upazila of Sylhet district on Wednesday, police said.
While Alima Begum, 34, and the two kids -- Mizan, 9, and Anisa, 4 -- succumbed to their injuries, her husband, Hifzur Rahman, is currently battling for his life at Sylhet Osmani Medical College and Hospital.
Abdul Ahad, the officer-in-charge of the Goainghat police station, said that neighbours found the family members lying in a pool of blood after they broke open the door hearing Hifzur groaning with pain.
Later, cops were informed and a team from the local police station rushed to the spot and took the bodies into custody. A seriously injured Hifzur has been admitted to the hospital.
The motive behind the crime is not clear, the official said.