The students squatted in front of the institute at Karumathampatti, about 25 km from here, raising slogans against the secretary and demanded his immediate removal, police said.
They alleged that the secretary regularly shows students obscene pictures and makes vulgar gestures, leading to mental depression among many of them.
The students also said four of their friends who took on the official were left alone during a study tour, creating a psychological fear among them.
The issue is being discussed by the management, police said.
