Police have arrested the father of the key accused, who killed teacher Utpal Kumar Sarkar with cricket stump in Savar, from Kushtia district.
"Ujjal Hossain was arrested from a house in Kumarkhali upazila during a raid. The accused student will be held soon," said Ashulia Police Station OC Kamruzzaman on Wednesday.
Ashulia Police Station said Utpal Kumar, 35, was killed after being hit by a student of class X with a cricket stump on June 25 while the teacher was watching girls' cricket tournament on the school playground.
Utpal was a lecturer in the Political Science department and chairman of the disciplinary committee at the Haji Yunus Ali School and College in Chitrasail area of Ashulia for almost 10 years.
Later on Sunday (June 26), the deceased's elder brother filed a case against some unknown persons mentioning the name of the accused student.