A four-month pregnant girl was killed allegedly by her husband and in-laws over dowry at Dhamor Uttarpara village in Phulbaria upazila of the district on Tuesday.
Police yesterday arrested the victim's husband and mother-in-law in connection with the killing.
The arrestees are Shamim Ahmed, 20, son of Hurmot Ali, and his mother Rokeya Begum, 48, of the village.
The deceased was Shimu Akter, 15, daughter of Sirajul Islam Siraj of Dhamor Beltoli village, said Sheikh Kabirul Islam, officer-in-charge of Phulbaria Police Station, adding that she was also a Class VIII student of a local school.
Quoting the victim's family members, the OC said farmer Shamim often tortured Shimu for dowry after nine months of their marriage.
Shamim and his family members strangled Shimu following an altercation over the issue early Tuesday.
On information, police recovered the body and sent it to Mymensingh Medical College Hospital for autopsy.
Shimu's father filed a case, accusing Shamim and his parents, said the police official.
The arrestees were produced before a court that sent them to jail, he said.