Around 2,000 protesters blocked car ferries from crossing the Suez Canal after a court ruled that 21 soccer fans would be sentenced to death, witnesses told Reuters.
Protesters reportedly also untied moored speedboats used to supply shipping in a bid to disrupt passing vessels.
Military police recovered five boats and brought them back to shore in Port Said, but two were still drifting, one witness said.
More top news
Staying cloudy for most throughout the afternoon but it will feel very mild for December.
The former King Crimson frontman and one third of supergroup Emerson, Lake & Palmer will also be remembered for a novelty festive hit.
The "murderously efficient" Islamic State is currently plotting violent attacks against the UK from Syria, the head of MI6 has warned.