Several thousand people are taking part in a protest in Cairo's central Tahrir Square on Friday.
The "Friday of Retribution" rally comes after hundreds of people were injured on Wednesday as Egyptian police clashed with anti-government protesters in the square. Tahrir Square was also the focus of February's uprising that forced President Hosni Mubarak from power.
The fresh protests are calling for faster political reforms and to demand that officials found guilty of abuse be brought to justice.
Another rally in Cairo is scheduled for next Friday. Youth movements say they will demand the immediate adoption of a new constitution.
The participants of the "Friday of Retribution" said they had lost confidence in the Interior Ministry and its officials and demanded its reform. Police say protesters tried to storm the ministry on Wednesday.
Activists are also calling for the trial of former interior minister Habib al-Adly, who is being investigated for ordering the killing of protesters during the revolution on January 25.
Al-Adly was sentenced to twelve years in prison in May and fined close to 15 million Egyptian pounds ($2.5 million) on charges of corruption.
Mubarak is currently in a military hospital awaiting trial on charges of ordering the murders of protesters during February's uprising. His sons, Alaa and Gamal, will also go on trial on August 3.
Last week, former Trade Minister Rachid Mohamed Rachid was given a five-year jail term in absentia for siphoning off public funds. Former Finance Minister Yussef Boutros Ghali was sentenced to 30 years in prison in absentia for large-scale graft earlier this month.
