About 150 million workers across India went on strike on September 2 to protest the "pro-business" policies of the Narendra Modi-led BJP government.
Trade unions are opposing government plans to sell off stakes in state-run companies and change labour laws, which will put jobs at risk and worsen working conditions.
AFP reported that the government's proposals would allow companies with up to 300 workers sack employees without government permission, up from the existing cap of 100. The changes would also increase barriers to unionising workplaces.
Unions are also demanding the government improve the set a national minimum wage of 15,000 rupees ($250) a month. Now the minimum wage differs from state to state and ranges from 5000 to 9000 rupees.
The BBC said that the strike hit public transport, with long queues of commuters and school children seen at a bus stops in many cities, including the capital, Delhi. Many passengers were also stranded at railway stations and airports.
Hawkers, domestic workers and daily wage labourers also joined the strike, AFP said.
A large number of schools and businesses were shut in the states of West Bengal and Kerala, where unions enjoy significant clout, the BBC said.
The Associated Chambers of Commerce and Industry of India estimated $3.7 billion in economic losses from the strike, singling out the country's ports where exports were left lying on the docks.