A strike called by India's biggest trade unions to protest against rising prices and lack of jobs has shut down two states ruled by the communists.
The strike shut down the eastern city of Calcutta
Schools and offices have remained closed and transport has been disrupted in the eastern state of West Bengal and in the southern state of Kerala.
In the capital Delhi, thousands of people attended a large rally to mark the protest.
However the strike has had little impact in the rest of the country.
RA Mittal, secretary of Hind Majdoor Sabha trade union said the government had been "callous" in addressing the concerns of labourers in the informal sector and farming.
"We are also demanding that the price rise be contained," he said.
Call centres spared
In the communist-ruled West Bengal state, the 24-hour strike has resulted in a complete shut-down.
Thousands of armed police have been deployed across the state.
Public transport has been paralysed. Streets in Calcutta and other towns of the state are empty. Most of the flights in and out of the city have been either cancelled or rescheduled.
Banks and other businesses have been closed. And Calcutta and Haldia sea ports have seen severe disruptions.
Essential services have not been affected by the strike, officials say.
A rally in Delhi to protest against the government's economic policies
Technology firms and call centres in the Calcutta area are also said to be functioning normally.
Most of their employees either stayed overnight at the offices or were brought in very early by company transport before the strike started.
"A lot of us arrived in office just after dawn, but I am not sure how we will get back home," IT executive Sumanta Ganguly was quoted by news agency Reuters as saying.
West Bengal Chief Minister, Buddhadeb Bhattacharjee had urged trade unions not to prevent people from going to work, specially in the IT sector - a call protestors appear to have accepted.
"Our supporters will not force anyone to join the strike," said Bengal's Marxist trade union chief, Shyamal Chakrabarti.
The strike was also widely observed in the southern state of Kerala.