Massive protests are underway in India against major economic reforms announced by the government last week, including plans to open the country's retail sector to global supermarket chains..
Organisers expect tens of millions of people to take part.
Protesters also object to planned rises in diesel oil and cooking gas prices.
Workers blocked railway tracks in Uttar Pradesh and Bihar states, and the opposition strongholds of Calcutta and Bangalore were virtually shut down, the BBC reports.
Ministers say the reforms are essential to revive India's slowing economy.
A key ally left the ruling coalition in protest, although its majority in parliament is not at immediate risk.
The Congress-led government attempted to introduce the retail reforms last year but backed down in the face of opposition.
Thursday's nationwide strike, called by the main opposition Bharatiya Janata Party (BJP), its allies and Communist parties, has shut down schools, businesses and public transport in many cities, the BBC says.