Over 400 school children in three districts fell ill after consuming food served under the Karnataka government's midday meal scheme called Akshara Dasoha.
As many as 265 cases were reported from three primary schools in Davangere town.
The state police control in Bangalore said 130 were affected at Guttulu in Mandya district while a report from Hubli said 20 children faced a similar condition in Navalgund town of Dharwad district.
However, none of the cases is life threatening, official sources said.
Seeing the plight of their children, some irate parents allegedly pelted stones at government buses in Navalgund.
The reports came a day after a similar case involving 234 children at Naragund, Benahatti and Chikkanaragund towns in Gadag district.
Naragund had also been tense after the incident.
Davangere Superintendent of Police Sunil Agarwal said the children were treated at the district hospital, with 15 being admitted as in-patients.
Agarwal said that midday meals in 41 centres had been stopped for two days and in three places, the children had refused to eat the meals.
A case has been registered against the voluntary organisation entrusted with the task of supplying meals to primary schools in Davangere, he said.
Food samples have been collected and sent for chemical analysis.
Earlier on Thursday, taking a serious view of the suspected food poisoning, involving the 234 children, the state government had ordered an enquiry.
Chief Secretary B S Patil said that the Gadag district Deputy Commissioner had been entrusted with the enquiry and told to initiate action against those responsible for the lapse.
Water Resources Minister H K Patil, who is in charge of Gadag district, paid a visit and ordered a laboratory test of the foodgrains used in the meals on Thursday.
Later, after a review meeting in Bangalore, Patil said steps would be taken to find a solution to the shortcomings in the scheme.
The government had on July one extended the midday meal scheme, now in operation in seven districts, to the entire state.