A court ruling on deadly football riots in Egypt has sparked fresh violence in two cities.
Protesters torched buildings in Cairo and tried unsuccessfully to disrupt international shipping on the Suez Canal.
Security sources told Reuters a man in his 30s and a young boy died in Cairo from the effects of tear gas and rubber bullets.
The Port Said stadium riot took place in February last year and claimed 74 lives when clashes broke out between rival fans of local club al-Masry and Cairo's al-Ahly team.
Spectators were crushed when panicked crowds tried to escape from the stadium after a pitch invasion by al-Masry supporters. Others fell or were thrown from terraces.
The court upheld death sentences given in January to 21 Port Said football fans, and gave prison terms to 17 other defendants.
The ruling enraged residents of the city at the northern entrance of the Suez Canal.
But it also angered rival fans in Cairo by acquitting a further 28 defendants including seven members of the police force.
Local al-Ahly fans in Cairo vented their rage at the acquittals, setting fire to a police social club, the offices of the Egyptian soccer federation and a branch of a fast food chain.
In Port Said, where the army took over security in the city centre from the police on Friday, about 2,000 residents blockaded ferries crossing the Suez Canal. Witnesses said youths also untied moored speedboats used to supply shipping on the waterway, hoping the boats would drift into the path of passing vessels.
Authorities controlling the canal said traffic had not been affected and the canal was safe for shipping.