Officials in eastern India say at least 20 children have died after eating a free lunch cooked in the school's kitchen.
Bihar state authorities say at least 27 other students were hospitalized after eating a meal that included rice and lentils Tuesday at a primary school in Masrakh, about 90 kilometers north of Patna, the state capital. Ten of those children are in critical condition.
Angry demonstrators staged a protest following the children's deaths.
An education minister says a preliminary investigation indicates the food contained traces of phosphorous. Few other details were immediately released.
Many state governments have launched midday meal programs for millions of poor children. Malnutrition is a major health issue for Indian children.