CHENNAI: Police arrested 21 persons when they attempted to march towards the residence of actor Rajnikanth here on Wednesday.
The police said the arrest was made only as a preventive measure.
The group comprised primarily farmers in Thanjavur district and were led by an advocate.
The activists said that film actors from Tamil Nadu should come together and stage a demonstration, as was done by the artists in Karnataka recently, to show their solidarity with the farmers on the Cauvery issue.
The Teynampet police registered a case under Section 151 IPC.
However, the volunteers were released in the evening, said the Deputy Commissioner of Police (Mylapore), A. G. Mourya.