Sixteen children died and 80 fell ill after consuming a mid-day meal at a primary school in Bihar's Saran district on Tuesday.
Principal secretary, education, Amarjeet Sinha said, "We suspect it to be organo-phosphorous poisoning caused by insecticides." He did not rule out the use of contaminated oil.
The Dharma Sati Gandaman village where the incident took place is 25km from the city of Chhapra, which falls in the constituency of Rashtriya Janata Dal chief Lalu Prasad. The party declared a bandh in Chhapra for Wednesday.
After Bodh Gaya, Tuesday's incident has also given friend-turned-foe BJP another stick with which to beat chief minister Nitish Kumar. State BJP leader Giriraj Singh said on Tuesday that Kumar has become more dangerous for the state than even Lalu.
Kumar has ordered a probe into the deaths and announced a compensation of Rs 2 lakh for the family of each of the dead. The district magistrate said the scheme's coordinator for the school has been suspended.