Four persons, suspected to be supporters of naxalites, were arrested near Dharmapuri on Friday.
According to police, they were rounded up for planning to disrupt the World Classical Tamil Conference at Coimbatore.
On a tip-off, a special team swung into action and arrested P. Nanjappan, an activist of the People's Democratic Youth League (PDYL); P. Vadivel, district in-charge, Anti Imperialist Movement; and two of its cadre P. Laxmanan and B. Sivan.
Judicial custody
They have been remanded to judicial custody for 15 days. Cases have been registered against them.