At least 98 pupils at two Menoufiya schools were hospitalised after eating school meals, the health ministry's Menoufiya office said on Tuesday.
In statements to Al-Ahram Arabic website, the ministry's deputy at the governorate, Hanaa Sarour, said the pupils at a school in Bagoor town and at a school in the neighbouring town of Sirs El-Laban were transferred to local hospitals after they ate the school meal, which consisted of biscuits.
Seventy-two have since been released.
Sarour said that samples from the meals were taken to laboratories in order to examine the reasons behind the suspected food poisoning.
The incident comes only a week after an estimated 3,353 pupils in the Upper Egyptian governorate of Sohag became ill after eating school meals.
President Abdel-Fattah El-Sisi has ordered the case be investigated.
The meals -- which are disbursed through the ministry -- included cheese and halva, a confectionary.
However, the health ministry announced on Monday that samples from some ill students had not shown the reason for the pupils' sickness.
Egypt has been aiming to expand its school food programme through its state-run National School Feeding Programme (NSFP) which covers 13.5 million students with a total budget of EGP 957 million.
The World Food Programme has been supporting the NSFP since 1968, and currently contributes fortified meals to 636,000 children nationwide.
El-Sisi has said previously that expansion of the NSFP is a priority for the state.
The European Union is one of the major contributors to school food programmes in Egypt, along with the United States, Germany and private-sector donors.