Patna - Twenty children have died and more are sick after eating a free meal at a primary school in eastern India, a state government minister said on Wednesday.
"It is sad but true that 20 children died after eating their midday meal, which appears to be poisonous," Bihar state education minister P K Shahi told AFP.
The death toll rose from eight on Tuesday and some 30 more children were still sick in hospital in the state capital Patna, the minister said.
A investigation is under way into the incident on Tuesday afternoon at the state-run school in the village of Masrakh, in Bihar's Saran district.
Several hundred people staged protests against the state government over the incident. Children started falling sick after eating their lunch of lentils and rice cooked at the school, officials have said.
"Hundreds of angry people staged a protest in Saran since late Tuesday night, demanding stern action against government officials responsible for this shocking incident," district government official S K Mall said.
Free meals are offered to impoverished students in state-run schools as part of the government welfare measures in many of India's 29 states.
Bihar is considered one of India's poorest states and is also the most populous.
Free lunches are hugely popular with poor families and educators see the meals as a way of increasing school attendance.
But children often suffer from food poisoning due to poor hygiene in school kitchens and the sometimes sub-standard quality of the food.
Food prices have soared in India over the last six years, causing increased hardship for the 455 million people estimated by the World Bank to live below the poverty line.