UNB, Sylhet :Two cases were filed on Saturday against 370 unidentified people in connection with Thursday’s Chhatra League infighting at Shahjalal University of Science and Technology (SUST) that left a BCL man dead.Pratibha Das, mother of slain BCL activist Sumon Chandra Das, filed a murder case against 120 unnamed people with Jalalabad police station.Meanwhile, Ishfakul Hossain, SUST registrar, also filed a case against 250 unnamed people with the same police station for unleashing violence on the campus.Earlier, police filed another case against 250 people on Thursday night in connection with the incident.Police arrested 21 BCL activists from different areas in the city for their suspected involvement in Thursday night’s violence.Earlier, Sumon Das, 22, an activist of Bangladesh Chhatra League (BCL) was killed and 17 others were injured in a factional clash of the ruling party’s student wing over establishing supremacy on the Shahjalal University of Science and Technology (SUST) campus on Thursday morning.Later, the authorities concerned of the university announced to close the University for sine die following the incident.A three-member probe committee, headed by SUST professor Dr. Ilias Uddin, has been formed to investigate the incident.