The Left party, however, denied any involvement.
The two Youth Congress activists - Krupesh, 19, and Joshy, 24 - were attacked by three assailants who came on motorcycles and seriously injured.
While Krupesh breathed his last at the Kasargode district hospital, Joshy died while being taken to a hospital in Mangaluru in neighbouring Karnataka.
The Kasargode unit of the Congress has called for a dawn-to-dusk shutdown in the district on Monday to protest the murder.
Addressing the media at Kochi after hearing about the incident, Ramachandran said that this murder was a planned one executed by the goons attached to the CPI-M.
"Chief Minister Pinarayi Vijayan who also holds the Home portfolio should explain this ghastly incident. This is not acceptable to the Kerala society. Its high time that the CPI-M directs its cadres to lay down arms," he said.