At least 300 have been injured, local media reported, in ongoing clashes between security forces and protesters who are angered by the verdicts related to a February brawl in which 74 soccer fans were killed.
President Mohammed Morsi canceled a scheduled trip to Ethiopia on Saturday and instead met for the first time with top generals as part of the newly formed National Defense Council.
The military was deployed in Port Said to try to restore stability, but assaults continued into the evening.
Saturday's unrest was the latest in a bout of violence that has left a total of 38 people dead in two days, including 11 killed in clashes between police and protesters marking Friday's second anniversary of the uprising that ousted longtime leader Hosni Mubarak.
The clashes broke out as protesters demonstrated against the Muslim Brotherhood and Morsi amid widespread calls for change and growing charges of injustice.
"Egyptians are very worried about what is happening because they feel the country is getting into a very difficult situation," said Said Sadek, professor of political sociology at the American University in Cairo.
(KUSA-TV © 2013 Multimedia Holdings Corporation)