Cases were registered under various IPC sections including 341 (wrongful restraint) and 324 (voluntarily causing hurt by dangerous weapons or means) against Valarmathi, MLA Senthamil and 54 AIADMK workers last night, Salem Range DIG Sanjay Kumar said.
The DMK activist, Murugan, has been admitted to hospital.
AIADMK workers had allegedly damaged the Thumbal Panchayat President (DMK) Ganesan's car and attacked the driver Murugan yesterday.
A criminal case had been registered against AIADMK MP Thambidurai on November 24 for allegedly threatening a DMK worker, while former DMK minister E V Velu and some DMK workers were booked earlier for allegedly verbally abusing and threatening AIADMK MLA S P Velumani while campaigning.
Arch rivals DMK and AIADMK are locked in a bitter battle in the bypoll, which was necessitated following the death of AIADMK's C Perumal. DMK's V Maran and AIADMK's P Saroja, Perumal's wife, are in the fray.
With hardly a week left for campaigning to end, ruling AIADMK and DMK have been trading charges against each other.
Cases have also been registered against some DMK functionaries following complaints from AIADMK that they were distributing cash to voters.
On the other hand, the DMK has lodged complaints with the Election Commission of India, accusing ruling AIADMK of violating the model code of conduct.