The following article by Debdutta Ghosh, Mou Chakravarty and Drimi Chaudhuri is from the Hindustan Times:
Charu Majumdar is dead for about 40 years. Kanu Sanyal is 78, ill and infirm, staying at his native village in north Bengal. Asim Chatterjee has mellowed. But Naxals — in their new avatar — are coming back to Kolkata.
On June 28, 1967, Radio Peking (in China) called it ‘The Spring Thunder’. The occasion was the May 1967 rebellion in north Bengal’s Naxalbari by a small breakaway faction of the Communist Party of India (Marxist).
Later, on April 22, 1969 — Russian revolution leader V.I. Lenin’s birthday — the rebels formed the Communist Party of India (Marxist-Leninist). But the announcement was made earlier at a public rally in Calcutta (the old name of Kolkata) by Kanu Sanyal on May 1 that year. The thunder fizzled out by 1972.
After spending about 35 years in the wilderness, the Marxist-Leninists morphed into the Communist Party of India (Maoist) in 2005 — after dividing and reuniting several differing factions operating almost independently.