Police have arrested the head of a school in eastern India where 23 children died after eating a free meal laced with a lethal pesticide.
The children, aged four to 12, fell ill within minutes of eating the lunch of lentils, potatoes and rice cooked at their primary school in a poverty-stricken village in Bihar state on July 16.
"The principal surrendered… and we have arrested her for questioning," said Sujeet Kumar, police chief of Saran district where the incident occurred.
"We need to talk to her first before framing charges," the official said by telephone.
Police have been searching for the teacher, Meena Devi, who apparently fled shortly after the tragedy in Gandaman village, which also left some 30 children ill in hospital and sparked angry street protests.
Saran district administrator Abhijit Sinha says the teacher is key to resolving the issue of just how the deadly chemicals ended up in the food.
"She is the right person to explain how the poison was mixed with the cooking oil," Sinha said.
Oil used to cook the food contained an agricultural insecticide that was five times the strength sold in the marketplace, a forensic report after the tragedy found.
Police said they raided Devi's home in the village last week where ingredients for the meal and cooking oil were kept.
Anguished parents buried many of the children on a playing field next to the primary school, in protest against the tragedy.
Some of the poverty-stricken parents told how they had only sent their children to the one-room school to ensure they received at least one meal a day.
Others have said their children survived after refusing to eat the food because of its foul odour. Children started falling ill within minutes of eating the meal.