A senior electoral official said "altercation caused disruption," even as the two rival sides charged each other with roughing up counting agents.
Another official said police restored peace and that the second round of counting was on.
"Police restored peace, Nothing alarming. Compilation of the second round going on," he said.
At the end of the first round, official AIADMK candidate Madhusudhanan was trailing sidelined party leader Dhinakaran by about 2,600 votes.
Disclaimer: No Business Standard Journalist was involved in creation of this content