They were on their way to Chennai to participate in a protest demanding 20% reservation for Vanniyars.
At least 250 cadres of the Pattali Makkal Katchi (PMK) were taken into preventive custody in Cuddalore district on Tuesday when they were proceeding to Chennai to take part in a protest called by the party to demand 20% reservation for Vanniyars.
Police sources said that security had been tightened at all check posts and the cadres were detained as a precautionary measure.
In Villupuram district, about 55 PMK cadres were detained when they resorted to a road roko at Kooteripattu, Melpettai and Mailam to protest against the police preventing party cadres from proceeding to Chennai.
However, no arrests were made in Kallakurichi district. Police sources said that heavy police force was deployed at the toll gates at Ulundurpet and Madur in the district.