Phan Thuong My, 44, faces charges of "intentionally causing injuries."
According to the police, My's son, a ninth grader, lost a calculator more than two weeks ago and accused a classmate identified only as K. of stealing it.
The boys are students at the La Ha Town Secondary School in Tu Nghia District.
K. told his mother about it.
She called My and his wife on the phone to tell them her son had not stolen the calculator.
The next day another student returned the calculator to My's son.
K. then wanted My's son to apologize for the false accusation, which led to arguments between them, and My became aware of it.
At around noon on Dec. 8 he followed K., who was on a bike, after school on his motorcycle, drove alongside him and started to yell at him.
In scenes captured on a security camera, he stopped K. in the middle of the empty street and hit him repeatedly on his face, chest and head.
He then left the boy on the street.
Shortly afterward passers-by rushed K. to Tu Nghia District’s medical center as he threw up and bled from his nose.
He was then transferred to the Quang Ngai General Hospital, where he was diagnosed with an intracranial lesion.
He also suffered injuries to 12% of his body and was under treatment as of Tuesday.
Vo Thanh Nho, the school principal, said teachers and staff at the school were aware of the case from the beginning, and after it became clear that K. did not steal the calculator his family only wanted My's son to apologize, but My's family refused.