Hundreds of supporters of toppled Islamist president Mohamed Morsi stormed and torched the Giza governor's office Thursday afternoon, Al-Ahram Arabic news website reported.
A group of Morsi backers meanwhile blocked Cairo's major Ring Road in both directions, bringing traffic to a complete halt.
Egypt has been convulsed in unrest, triggered by a deadly security crackdown on pro-Morsi Cairo protest camps, in which more than 500 people have been killed and thousands others injured.
