Ramakrishnan, Rajya Sabha MP T K Rangarajan and senior state leaders and MLAs A Sounderrajan and G Beemarao were among those held, police said.
An Indian fisherman was killed and three others wounded on July 16 when a security team onboard a US Navy ship fired at their small boat off Dubai, drawing flak from political leaders in the state, including Chief Minister J Jayalalithaa and DMK chief M Karunanidhi.
