There were clashes in Cairo on Saturday after a judge dismissed charges against former President Hosni Mubarak.
The 86 year-old had been facing trial over the killing of protesters during the 2011 uprising against him.
Several thousand demonstrators took to the streets in anger at the verdict and were met with water cannon and tear gas. Members of the banned Muslim Brotherhood group also joined the protest.
Mubarak still remains behind bars, however, as he is serving a three year sentence for a separate offence of embezzlement.