The deceased were identified as Bellal Hossain of Taltoli upazila, and his 10-year-old step-daughter Karina Akter. The injured was named as Sajenur Begum, 30, of Patharghata.
Hanif Shikdar, officer-in-charge of Patharghata Police Station, said that Bellal and Sajenur got divorced one and half months ago. Since then, Sajenur and her daughter lived in Ruhita village.
Bellal broke into their house around 2:30am and poured petrol on the sleeping duo before setting them on fire. Karina died on the spot while Sajenur suffered 80 percent burns.
Police recovered Karina’s body and sent Sajenur to local hospital. The woman was shifted to Barishal Sher-e-Bangla Medical College Hospital.
Bellal later reportedly committed suicide. His body was recovered in the morning.