They said the teacher Subramanian scolded 20 of his students for not doing class works and examinations properly. The inebriated students went to Subramanian's house, took him out in a car and thrashed him.
He suffered external injuries in the attack. The teacher informed his relatives about the insult and hanged himself when they were asleep, police said.
Tension prevailed in the area following the incident and police arrested five students including Selvam, Pradeep and Pillaikumaram and were looking for the others. A driver of the Institute and his wife were also beaten up by the students, police said, adding the motive behind it is being investigated.