A wave of strikes has hit India, with shops and businesses closing across the country. The demonstrators oppose the government's decision to allow foreign retailers such as Walmart and Tesco to enter the Indian market. Small shopkeepers, traders, laborers and opposition activists blocked roads and railways across India on Thursday, part of a nationwide strike against a host of government reforms that aim to boost the country's flagging economy. Prime Minister Manmohan Singh announced the controversial reforms last week, which would allow the world's three largest retailers - Walmart, Carrefour and Tesco - to invest in India's supermarket sector. The reforms would also allow foreign investment in aviation and the sale of minority stakes in four state-run companies. The government has also hiked diesel fuel prices by 12 percent in a bid to reduce its budget deficit. The opposition Bharatiya Janata Party (BJP) as well as several regional and leftist parties called the nationwide strike. Protesters demonstrated through the city of Kolkata in West Bengal state, blocking national highways and railways. Activists from the BJP and its allies also gathered at trains stations in Bihar state in north India, forcing train service there to stop. "Protesters have tried to target trains and bus stations and [we expect] they will also target shops and business establishments," said Ravinder Kumar, a senior police officer in Patna, the capital of Bihar. Shopkeepers concerned The Confederation of All India Traders (CAIT) estimates that some 50 million people will take part in the protests. Shops and commercial establishments were closed in towns across the states of Bihar, Orissa, Uttar Pradesh, Andhra Pradesh, Karnataka, Maharashtra and Punjab. New Delhi has argued that opening the country to foreign retail investment would offer consumers more choice and create new jobs while also enabling farmers to reduce waste. But small shopkeepers are concerned that the arrival of large supermarket chains from abroad could force them out of business. The CAIT estimates that around 220 million Indians are dependent on some 50 million small shops, called kiranas.