Four people were killed and 15 were injured in confrontations in Alexandria, Cairo, Suez, Minya and Sharqiya on Friday, the health ministry said.
The ministry added on Saturday that local hospitals have received four bodies, one from Alexandria and three from Suez.
It added that the injured were also transferred to local hospitals to receive medical attention.
An Islamist alliance, which supports the Muslim Brotherhood's ousted President Mohamed Mursi, had called for demonstrations across the country on Friday against Tuesday's constitutional referendum.
Egyptians will vote on a new constitution on Tuesday and Wednesday.
The interior ministry has said it arrested 169 "troublemakers" in the clashes.