A man injured in the clash in Kolkata's Esplanade being carried away.
Supporters of the Socialist Unity Centre of India party or SUCI clashed with the police today in the heart of Kolkata as police prevented them from marching towards the Governor's residence, Raj Bhavan.
The SUCI claimed 250 of its 30,000 supporters who had gathered for the protest were injured, 33 of them seriously.
The police said there were about 10,000 protestors and even five policemen were injured in the clash.
The SUCI, which was on a protest over Central policies and the lack of law and order in the state, was holding a march to the Governor's House when they were stopped by the police at Esplanande.
As the protesters shouted slogans and insisted on moving forward, the police used batons to stop them. The SUCI members retaliated. Many of the injured could be seen being carried away from the spot.
SUCI leader and former member of Parliament Tarun Mandal later said 250 party members were injured -- 33 of them have been hospitalised. The rest were released after first aid.
Mr Mandal said 30,000 people had gathered for the protest against a number of Central policies including privatization of banks and insurance, disinvestment, and the recent visit of US President Barack Obama.
Apart from the law and order, the state issues they opposed included the lack of safety for women and the "disintegration" of the education system, Mr Mandal said.
The SUCI was also protesting the death of Howrah braveheart Arup Bhandari. His family claims he was killed for protesting against some men harassing women. The chief minister has said his death was the result of a clash between local gangs.