A sixth-grader was killed after allegedly being raped by four unidentified people at her home in a remote village here on Tuesday night.

The victim's mother, who was at home with her two minor sons when the incident took place, was also sexually abused, alleged her relatives.

However, police later detained her for “interrogation” and did not allow journalists to talk to her.

The deceased, aged about 11, was a student of Mohipur Cooperative High School in Patuakhali's Kalapara upazila.

According to relatives, the girl's mother was sleeping with her two sons aged 2 and 3 on the ground-floor of their two-storey tin-roofed house in Sirajpur village around 8:30pm. The children's father, a carpenter by profession, was away from home.

Hearing the wailing mother, locals rushed to the spot. But the criminals had left the house by then.

The schoolgirl's bloodstained and unconscious body was rescued from the first floor. She was rushed to Kuakata Hospital where doctors declared her dead.

Talking to The Daily Star, victim's uncle said, “Four people with their faces covered by cloth entered my brother's house and sexually tortured my niece.”

The criminals also sexually abused her mother, he alleged.

An aunt of the schoolgirl said the criminals taped the baby boys' mouths.

Arifur Rahman, medical officer at Kuakata Hospital, said the girl had passed away before she was taken to the hospital.

Her body bore several marks of torture. The cause of her death would be confirmed by forensic tests, he added.

Abdus Salam, headmaster of Mohipur Cooperative High School, demanded exemplary punishment for the killers.

Mizanur Rahman, officer-in-charge of Mohipur Police Station, said they detained the victim's mother for interrogation.

He said the schoolgirl's father filed a murder case with the police station yesterday accusing unidentified people.

Police said the victim's body was handed over to her family members after an autopsy was carried out on it at Patuakhali General Hospital morgue.