A 62-year-old woman and her one-and-a-half-year-old granddaughter were killed allegedly by the woman’s son at Boroshalghor village in Debidwar upazila of Cumilla on Monday morning.
The deceased were identified as Peyara Begum, wife of Farid Mia of the village and her granddaughter Ishrat Zahan, daughter of Md Sujon.
Officer-in-Charge of Debidwar Police Station Md Moniruzzaman said Emon, 24, hacked his mother Peyara with a sharp weapon around 8:30am, leaving her dead on the spot.
Later, he slammed his niece Ishrat onto a bed, leaving her dead too.
When Ishrat’s mother Rabeya tried to resist him, Emon hit her with the sharp weapon, leaving her injured.
The injured woman was first taken to Debidwar Upazila Health Complex, from where she was referred to Cumilla Medical College Hospital for better treatment.
Hearing screams, local people rushed to the house and found Peyara's body lying on the floor and the infant's body on the bed.
They also caught Emon and locked him inside the house before police arrived and took him into custody.
Sujon said Emon had been staying at home for the past eight months after breaking one of his legs while playing football.
He underwent two surgeries, after which he began showing signs of mental health problems.
The motive behind the killings could not be known immediately.
The OC said they were investigating the incident.