Mettur MLA S R Parthiban and DMDK district secretary N Radhakrishnan were arrested in connection with cases booked against them under IPC sections including 188, Salem Superintendent of Police Aswin Kotnis said.
The arrest comes a day after DMDK Taluk secretary Karuppuzhagi was taken into custody and cases registered against eight others, including DMDK's Gengavalli MLA S Suba, for allegedly making some remarks against Chief Minister Jayalalithaa at a public meeting at Talavasal in the district on Monday night.
DMDK, the main opposition party in Tamil Nadu, is led by actor-politician Vijayakant.