NEW DELHI — A medical official in the eastern Indian state of Bihar confirmed Thursday that pesticide had contaminated the free school lunch that killed 23 children this week, triggering outrage among parents.
The children, most of them between the ages of 5 and 12, fell sick Tuesday at their school in the village of Gandamal almost immediately after eating the midday meal of rice, lentils, potatoes, and soy. Amarkant Jha Amar, the superintendent of Patna Medical College and Hospital in Bihar’s capital, said it appeared from postmortem reports that pesticide either was used instead of cooking oil or got mixed with the oil used to prepare the lunch.
‘‘This is not an ordinary food poisoning case, because the instant deaths means there was a large amount of poisonous substance,’’ he said.
The free midday meal program, which covers more than 120 million schoolchildren, was launched nationwide more than a decade ago with the goals of raising school enrollment and improving childhood nutrition. An independent survey in 2011 found that 4 out of 10 Indian children are severely malnourished.
More than 96 percent of children between the ages of 6 and 14 in rural India were enrolled last year, up from 81 percent in 2001, according to official data. The government says that the midday meal program contributed significantly to that improvement.
Although the program is widely regarded as a success, there have been many cases of tardy implementation and food poisoning. Tuesday’s horrific death toll underscored the concerns about failure to comply with standards.
‘‘The first violation: How did the cooking oil and pesticide mix? Second, when oil was poured into the pan, there was a foul smell and fumes arose, but the principal did not pay attention even after the cook complained,’’ Amar said. ‘‘The rules say that the cook or principal must taste the food first before serving it to the children. That rule was also violated.’’
Amar said 25 children and a cook were still in the hospital but out of danger. He added that officials are awaiting the final laboratory analysis of the ingredients found at the school.
Many government-run rural schools in India, especially in the impoverished state of Bihar, lack hygiene, infrastructure, electricity, and running water. Meals are often cooked in dank, windowless rooms hung with cobwebs and crawling with insects.
The national government’s guidelines for the program include suggestions such as storing food grains away from moisture in airtight containers, washing leafy vegetables before cutting, keeping kitchens clean and well ventilated, and hiring cooks who cut their nails and wash their hands.
But even those basic standards are routinely flouted, observers say.
‘‘The village schools are in such a sorry state, we frequently hear of lizards falling into cooked food, there is no cleanliness in the kitchen, and the budget is siphoned off by corrupt officials,’’ said Ajit Kumar, an activist in Patna who requested information about the program from officials two months ago.
On Thursday, officials suggested that foul play had not been ruled out.