The Left party alleged that BJP-RSS activists were behind the incident.
Three window panes, a flag pole and the signboard of a library were found damaged at the CPI(M) branch office at Swamikunnu in Dharmadam in Kannur district in the early hours, the police said.
A case under various sections of the IPC, including those dealing with unlawful assembly and trespass, has been registered in connection with the incident.
None had been arrested so far, the police said.
The incident comes close on the heels of peace talks held in Kannur, Kottayam and Thiruvananthapuram in the backdrop of a spurt in violence in the state, allegedly involving ruling CPI(M) and BJP-RSS workers, including the brutal slaying of a Rashtriya Swayamsevak Sangh cadre on July 29.
An all-party meeting had also been held in the state capital recently over the issue.
Union Finance Minister Arun Jaitely had visited the family of the slain RSS worker on August 6 and slammed the CPI(M) for the political violence in the state. PTI