A soldier sits on guard atop an armoured personnel carrier (APC) after night clashes in Cairo November 20, 2013. Egyptian police fired teargas to drive protesters out of Cairo's Tahrir Square on Tuesday, breaking up a demonstration commemorating 42 protesters killed two years ago while opposing the government that took power after Hosni Mubarak's downfall. REUTERS/Amr Abdallah Dalsh (EGYPT - Tags: POLITICS CIVIL UNREST MILITARY TPX IMAGES OF THE DAY)