Several vehicles were stuck on the old National Highway 6, which connects Kolkata to Mumbai, after an organisation of the Kudmi community started a blockade in West Bengal's Paschim Medinipur district on Tuesday, demanding that they be given ST status.
West Bengal Kudmi Samaj started the blockade around 6 am at Khemashuli in the Kharagpur local police station area, officials said.
"The blockade will continue until our demands are met," said Tapas Mahato, a leader of the organisation.
Hundreds of vehicles were stranded on the road because of the blockade, triggering massive traffic snarls even on the other adjoining roads in Paschim Medinipur and Jhargram districts.
Till the last report was received around 11 pm, the blockade was continuing.
Drivers of the stranded vehicles said they were facing scarcity of food and water.
Some of the vehicles were being diverted through Balibhasha in Jhargram to bypass the blockade, officials said.
Kudmis are at present classified as OBCs.
