Egyptian opposition leader Mohamed ElBaradei will be investigated by the prosecution for his comments that allegedly encourage violence.
Prosecutor-General Talaat Abdullah ordered the investigation after a legal complaint was filed by Salafist Al-Asala Party leader Mamdouh Ismail.
Mohamed ElBaradei had said on Twitter: "The violence and chaos will continue until Morsi and his associates listen to the public's demands for a new government, a democratic constitution and an independent judiciary."
Ismail's complaint said ElBaradei had violated his endorsement of the Al-Azhar document, which was designed to help end weeks of political unrest in the country.
ElBaradei had violated religious and democratic norms and international agreements, Ismail added.
Mohamed ElBaradei is co-leader of the opposition National Salvation Front.
At least 59 people have been killed and hundreds injured in nationwide protests since the second anniversary of the January 25 Revolution.