A protester opposing Egyptian President Mohamed Mursi wears a handmade mask to shield his face from tear gas during clashes with riot police at Qasr Al Nil bridge, which leads to Tahrir Square in Cairo January 28, 2013. Monday was the fifth day of violence in Egypt that has killed 50 people and prompted the Islamist president to declare a state of emergency in an attempt to end a wave of unrest sweeping the Arab world's biggest nation. REUTERS/Amr Abdallah Dalsh (EGYPT - Tags: POLITICS CIVIL UNREST)