The convicts are Abul Uddin, Babul Uddin, Russel Ahmed and Sadik Uddin of Kanaighat upazila.
It also fined them Tk one lakh each.
The tribunal also sentenced the convicts to seven years imprisonment and fined Tk 10,000 each for dumping the body of the girl after murder.
According to the prosecution, Sultana Begum, 12 went to her friend’s house Farzana on May 25, 2016.
Abul Uddin along with three other convicts violated Sultana in turns when they found her alone in Farzana’s house and killer her. Later they concealed the body digging a hole.
Sultana’s family lodged a general diary with Kanaighat Police Station, Sultana’s body was recovered on the following day.
Eklim Uddin, brother of the victim, filed a case with Kanaighat Police Station.
After examining the records and witnesses, Sylhet Women and Children Repression and Prevention Tribunal Judge AM Zulfiker Hayat handed down the verdict.