The glass panes of the office windows were broken when stones were hurled last night and the incident came to light this morning, Congress sources said.
Union Minister for Rural Development Jairam Ramesh today visited the DCC office and went around the area, sources said.
Police further strengthened security in the district after the attack, which has come close on the heels of the stone pelting incident during a LDF protest on Sunday last in which Chief Minister Oommen Chandy was injured.
Condemning the attack on the DCC office, Chandy said the culprits would be nabbed very soon.
Senior Congress leader and Kannur MP K Sudhakaram alleged that CPI(M) was behind the attack."CPI(M) will have to pay heavy price if they cross all limits.