Police arrested the head teacher at a school in India where 23 children died of food poisoning from a free lunch served to them.

Meena Kumari had been hiding since dozens of students at the school in eastern Bihar state fell ill.

She was turning herself in on Wednesday when police arrested her amid protests and outrage among the victims’ families as it emerged the food served to their children were laced with the deadly insecticide monocrotophos, reports the BBC.

Reports say the vegetable oil used to prepare the food was contaminated with toxic levels of insecticide. Kumar insisted the oil was “home-made and safe to use” when the school’s cook complained it “smelled strongly”.

Police were investigating whether the oil, believed to have been bought from the teacher’s husband, was kept in a container previously used to store pesticide.

Kumari face charges of murder and gross negligence for the deaths of the children.

The incident tarnished the government’s Mid-Day meal scheme, aimed at combating hunger and boosting school attendance, which provides free food for 120 million children in 1.2 million schools across India.

Teachers at state-run primary schools in Bihar, one of India’s poorest states, vowed not to participate in the scheme from Friday.