Clashes between anti-government protesters and police left 157 people injured in Port Said on Wednesday, the head of Egypt's Ambulance Authority Mohamed Sultan has said.
Two people were also injured during clashes in Ismailia.
Clashes broke out in Port Said on Sunday after the interior ministry transferred local residents accused of involvement in last year's Port Said disaster to a prison outside the city.
Fifty-two of the 73 defendants will hear their fates on Saturday. Twenty-one were sentenced to death last month for their involvement in the killing of over 70 fans of Cairo's Ahly football club at a match in the Port Said Stadium in February 2012.
Port Said, Ismailia and Suez, as well as the Nile Delta cities of Mahalla and Tanta, have been rocked by weeks of intermittent violence since the second anniversary of the Egyptian Revolution.
Calls for civil disobedience in the cities have been circulating since mid February, leading to sporadic violent clashes between security officers and protesters.