A case has been registered and further investigation is underway.
While the Chief Medical Officer (CMO) has ordered an inquiry into the matter, parents of the affected students have demanded strict action against the sugar mill’s employees and owners.
Two men -- Khaled Khayat and Mahmoud Khayat -- have been charged with terrorism offences
The men -- reportedly two Lebanese-Australian fathers and their sons -- were arrested in raids across Sydney on Saturday evening.
The mill had been closed for the last three days for repairs, he said, adding further investigation are on.
The tragedy occurred as the workers attended to a sewage tank pump.
Three members of a farmer's family and another farmer were killed because of a suspected poisonous gas emanating from a well in Imlia village in Badwara tehsil, about 50 km away from the Katni district.