Description:Opponents of President Mohamed Mursi marched to the presidential palace in Cairo on Friday, while thousands protested at Tahrir Square. The demonstrators are demanding Mursi's overthrow after the deadliest violence of his seven months in power. Protests marking the second anniversary of the uprising that toppled Hosni Mubarak have killed nearly 60 people since January 25, prompting the head of the army to warn this week that the state was on the verge of collapse.(1:14)