PATNA, India -- A police official says authorities have arrested the principal of a school in eastern India where 23 children died last week after eating lunch prepared with contaminated oil.

Superintendent Sujit Kumar said a police team investigating the deaths in Bihar state arrested Meena Kumari on Wednesday, nine days after she went into hiding.

Kumari fled as soon as the children began falling ill after eating lunch cooked in the school. Twenty-three children between the ages of 5 and 12 died from eating the meal and many others fell ill.

Forensic tests have revealed that the lunch served to the children contained toxic levels of a deadly pesticide.

Police were questioning Kumari to establish how the pesticide got mixed with the food, Kumar said.

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  • Indian children who fell sick after eating a free school lunch lie at a hospital in Patna, India, Wednesday, July 17, 2013. (AP Photo/Aftab Alam Siddiqui)

  • In this Tuesday, July 16, 2013 photo, schoolchildren receive treatment at a hospital after falling ill soon after eating a free meal at a primary school in Chhapra district, in the eastern Indian state of Bihar. (AP Photo)

  • An Indian man mourns as he holds his dead daughter inside an ambulance, outside a hospital in Patna, in the eastern Indian state of Bihar, Wednesday, July 17, 2013. (AP Photo/Aftab Alam Siddiqui)

  • A protestor vandalizes flower pots at the office of the free school lunch scheme in Patna, India, Wednesday, July 17, 2013. (AP Photo)

  • Indian children who fell sick after eating a free school lunch lie at a hospital in Patna, India, Wednesday, July 17, 2013. (AP Photo/Aftab Alam Siddiqui)

  • An Indian man cries while carrying the body of his daughter who died after eating a free school lunch at a hospital in Patna, India, Wednesday, July 17, 2013. (AP Photo)

  • In this Tuesday, July 16, 2013, an unidentified Indian man carries a boy who fell ill after eating a free school lunch to a hospital, in Patna, in the eastern Indian state of Bihar. (AP Photo)

  • In this Tuesday, July 16, 2013 photo, schoolchildren receive treatment at a hospital after falling ill soon after eating a free meal at a primary school in Chhapra district, in the eastern Indian state of Bihar. (AP Photo)

  • A grief-stricken mother (C), whose son died after consuming a free mid day meal at a school in India's Bihar state, is consoled at Gandaman in Saran District on July 17, 2013. (STR/AFP/Getty Images)