A section of the Pattali Makkal Katchi (PMK) cadre who were lodged at Salem Central Prison refused to have their breakfast on Wednesday.
Prison officials tried to make them give up their protest.
Condemning the arrest of their leader S. Ramadoss in Villupuram on Tuesday, PMK cadre staged road block in various parts of the district and were arrested by the city and the rural police.
A total of 535 cadre, including cadre from nearby districts, were lodged at the prison.
On Wednesday, when food was served to the inmates of the prison, a few cadre refused to eat, protested the arrest of their leader and sought his release.
However, prison officials pacified them and they had food in the afternoon.
Meanwhile, the city police arrested A. Murugan (32) and K. Thangaraj (35), both from Gorimedu, for breaking the windscreen of the government bus in Kannankurichi on late Tuesday night.
Buses plying to other districts were stopped for over three hours and later sent with police escorts.
Since miscreants pelted stones and damaged windscreens and glasses of nine buses, bus service in interior villages resumed only on Wednesday morning.
Police pickets were posted at important points across the district to prevent untoward incidents.