Expressing his condolences to the bereaved family, Karunanidhi in a statement said it was a painful to hear about the murder and added the violence that took place following the attack was "highly condemnable".
Referring to reports that anti-socials were involved in the violence, he alleged that of late such incidents were increasing day by day in Coimbatore.
"It is not desirable that after the incident, Hindu Munnani activists took law into their hands by threatening innocent people to close shops in Coimbatore," he said.
Karunanidhi also condemned incidents of petrol bombs being hurled at BJP offices in Dindigul and Coimbatore.
Sasikumar (36), the Hindu Munnani's Coimbatore district spokesperson was returning home on September 22 night at Subramaniampalayam on the outskirts of Coimbatore on his two-wheeler when unidentified assailants chased him on motorcycles and attacked him with sickles. He was taken to a private hospital, where he died.