Almost five hundred students have been struck down with food poisoning at Al-Azhar University.
Hundreds of angry students gathered on Monday night to protest deteriorating conditions at the university's hostels and negligence by management.
Some of the protesting students demanded the resignation of the university president and the student union released a statement demanding a prompt investigation into the incident.
Dozens of students blocked El-Nasr Street to protest that their repeated complaints about poor services had been ignored.
Student union member Abdullah Abdel-Moteleb told Al-Ahram Arabic website that meals served at the hostel on Monday were of noticeably poorer quality than usual. By around 6pm, dozens were suffering the effects of food poisoning and were taken to hospital, he added.
On Tuesday morning, the health ministry said 479 people from Al-Azhar had been hospitalised with food poisoning.
Students will gather at the university headquarters at 11am on Tuesday and march to the headquarters of Al-Azhar Sheikhdom.