"Castro was not just the leader of Cuban Communist party but the brave leader of world communist movement. Beyond that, he was the inspirational force of anti-imperialist movements the world over," he said in a statement here.
Describing Castro as a man of "strong and unparallelled personality", Vijayan hailed the challenges he had posed to the imperialist policies of the US.
Marxist veteran and former Chief Minister V S Achuthanandan said Castro's death was a "great loss" to humanity in these days as imperialist forces were spreading its roots globally.
Meanwhile, state opposition leader Ramesh Chennithala said Castro had always been an inspiration for those who fought against exploitation, injustice and oppression the world over.
He also recollected that the iconic revolutionary had been a good friend of India and had shared warm relations with former Prime Ministers like Jawaharlal Nehru and Indira Gandhi.
Sharing the same sentiments, KPCC president V M Sudheeran said Castro's passing away was going to be an irreparable loss to the world.