Crowds gather in Tahrir Square on November 22, 2011 in Cairo, Egypt. Thousands of Egyptians have been gathering in Tahrir Square after three days of deadly clashes with security forces despite a promise from Egypt's interim ruling Military council to bring forward Presidential elections. (Photo by Peter Macdiarmid/Getty Images)

A prototestor helps another suffering from the effects of tear gas near Tahrir Square on November 22, 2011 in Cairo, Egypt. (Photo by Peter Macdiarmid/Getty Images)

Protestors suffering from the effects of tear gas fired by police lie in a make shift medical centre in Tahrir Square on November 22, 2011 in Cairo, Egypt. (Photo by Peter Macdiarmid/Getty Images)

An injured protestor is led away during clashes with police near Tahrir Square on November 23, 2011 in Cairo, Egypt. (Photo by Peter Macdiarmid/Getty Images)