Hundreds of members of the Ultras Green Eagles - hardcore fans of Port Said's Masry football club - staged marches Friday demanding justice for the killing of protesters and the release of imprisoned fellow fans.
Anger erupted in Egypt's Suez Canal city of Port Said in January when 21 local residents were sentenced to death for their part in the killing of more than 70 Ahly club fans in Egypt's worst football disaster in February 2012.
More than 50 people have been killed and hundreds more injured when violent confrontations broke out with security when the verdict was announced.
This in turn sparked more protests demanding justice for those killed in the clashes.
Demonstrations went around the city Friday evening and ended at the security directorate where a number of protesters pelted the building with stones and set off fireworks. Six police cars were destroyed during the protests.
Security measures have been raised to emergency levels at the directorate and eight police stations in anticipation of any further action, according to state news agency MENA.
Port Said residents complain they are being used as the scapegoat for last year's deadly disaster in the stadium.
President Mohamed Morsi had assured in March that the rights of victims of violence that erupted in January following the verdict are guaranteed pending investigations.