Members of Rapid Action Battalion (RAB) on Wednesday detained the parents and a maternal aunt of the two siblings, who were found dead at home in the city’s Banasree area on Monday, from Jamalpur district for quizzing over the mysterious death, reports UNB.

The detainees are Amanullah, Mahfuza and Afroza Malek, father, mother and maternal aunt of the deceased respectively.

Assistant Superintendent of Police Abdul Karim, operation officer of Rab-3, said a team of the elite force detained the trio from Iqbalpur in Jamalpur Sadar upazila around 11:15am.

Later, they were sent to Dhaka for interrogation, the ASP added.

On the other hand, sources at Rampura Police Station said no case was filed as of 1pm in connection with the incident.

Earlier, on Tuesday, police detained four people — Pintu Das and Shaheen, caretakers of the house, victims’ relative Ferdous and house tutor Sheuli Akter — for interrogation over the death.

Based on their information, Rab detained the trio on Wednesday.

The two siblings — Nusrat Jahan Urmi, 14, a Class-VII student of Viqarunnisa Noon School, and her younger brother Alvi Aman, 6, a nursery student of Holy Crescent School in Banasree, were found dead at a home at the city’s Banasree on Monday night.

Family sources claimed that they died after having a Chinese restaurant takeaway.

However, autopsies, conducted by the forensic department of Dhaka Medical College Hospital, found injury marks on the throat of Urmi and on the throat as well as a leg of Alvi.