Members of Rapid Action Battalion (RAB) have arrested a man and his four associates from the city for "killing" his own daughter over his alleged extramarital affair in Debidwar upazila of Cumilla.
The arrestees are victim's father Md Amir Hossain, 25, Laili Akter, 30, Md Rabiul Awal, 19, Md Rezaul Islam Emon, 22, and Md Sohel Rana, 27.
All of them are from Cumilla's Debidwar upazila.
According to a media release of RAB Headquarters, a team of Rab-11 arrested them conducting a drive in the capital's Jatrabari area on Tuesday night.
Five-year-old Fahima went missing on 7 November and her father Amir filed a general diary (GD) in this regard on 11 November, prompting detectives to launch an investigation, the release said.
Later, police recovered Fahima's body packed in a sack from a waterbody in Debidwar upazila on Sunday.
On the same day, a case was filed against unidentified people at Debidwar Police Station.
During primary investigation, all the arrestees confessed to their involvement in the murder, said RAB.
Amir and Laila stabbed Fahima to death and dumped the body with the help of three others when the girl came to about the illicit relationship between them, it said.
Legal process is underway in this regard, the release added.