Riot police stand guard outside the presidential palace in Cairo, December 12, 2012.

Army tanks and riot police are seen outside the presidential palace in Cairo, December 12, 2012.

Protesters block the gate of a government building near Tahrir Square in Cairo, December 11, 2012.

egypt constitution

Anti-Morsi protesters shout slogans as they stand on top of a wall in front of the presidential palace in Cairo, Egypt, December 11, 2012.

Protesters chant anti-government slogans in Tahrir Square, Cairo, Egypt, December 11, 2012.

Egypt: Morsi showing the draft constitution

Anti-Mursi protesters chant anti-government slogans at Tahrir Square in Cairo, December 11, 2012.

Protesters gather in Tahrir Square in Cairo, Egypt, December 11, 2012.

People clash with anti-Morsi protesters, after the protesters blocked the gate of a government building near Tahrir Square in Cairo, Egypt, December 11, 2012.

A cleric from Al-Azhar, Egypt's most respected Islamic institution, addresses protesters in front of the presidential palace during a demonstration in Cairo, Egypt, Tuesday, Dec. 11, 2012.  (AP Photo/Petr David Josek)

Egypt: protest

Anti-Morsi protesters sit outside their tents, below a flag that reads, "No, to Constitution," Tahrir Square, Cairo, Egypt, December 10, 2012.

Egyptian walk next to graffiti and Arabic writing that reads at left, "no to the Muslim Brotherhood constitution," in Tahrir Square in Cairo, December 10, 2012.

Soldiers stand guard on top a tank in front of the presidential palace in Cairo, Egypt, December 9, 2012.

An anti-Mursi protester chants slogans on a newly built barrier in front of soldiers guarding outside the Egyptian presidential palace in Cairo December 9, 2012. A concession offered by President Mohamed Mursi failed to placate opponents who accused him o

Egyptian riot

Egyptian walk next to graffiti and Arabic writing that reads at left, "no to the Muslim Brotherhood constitution," in Tahrir Square in Cairo, Egypt,, Monday, Dec. 10, 2012. (AP Photo/Hassan Ammar)

Soldiers march while anti-Mursi protesters paint a mural outside the Egyptian presidential palace in Cairo December 9, 2012.

Protesters chant slogans during a demonstration in front of the presidential palace in Cairo, Egypt, December 9, 2012.

Protesters chant slogans during a demonstration in front of the presidential palace in Cairo, Egypt, Sunday, Dec. 9, 2012.

egypt

Protesters push army soldiers standing guard in front of the presidential palace in Cairo, Egypt, December 9, 2012.