Burials were held on Wednesday for three members of a family found dead in Chanderkola village of Kachua, Bagerhat.
Monira Begum and her son Ahad Hawlader were buried in the family graveyard in Chanderkola after funeral prayers at about 6pm.
Rashida Begum, Monira's mother and Ahad's grandmother, was buried at her home in Brishtipur village of Bagerhat Sadar.
Relatives and local community figures attended the funerals.
Police handed the bodies to relatives on Wednesday afternoon after post-mortem examinations at the Bagerhat 250-bed District Hospital.
The bodies were discovered inside their home in Chanderkola on Tuesday, after which they were sent to the hospital morgue following an inquest.
Faisal Hawlader, Monira Begum's elder son, filed a murder case at Kachua police station late on Tuesday against unidentified persons.
Police said they recovered a hammer described as linked to the killings, along with other evidence.
Police said they had not recovered phones used by Ahad Hawlader and Monira Begum or any valuables.
Faisal Hawlader alleged that the killings were planned and said cash intended for house construction, jewellery and phones were missing from the home.
Bagerhat Police Superintendent Hasan Mohammad Naser Riqabdar said teams from district detective police, Kachua police, the Police Bureau of Investigation and the Criminal Investigation Department were working on the case.
Police said they were pursuing multiple possibilities, while the motive and those responsible had not been identified.