Egyptian police lob a tear gas canister over a security barrier as youth retaliate with rocks.<br/> <br />It's a violent start to the second anniversary of Egypt's uprising that toppled Hosni Mubarak and ushered in an Islamist-led government.<br/> <br />By afternoon prayer time, thousands of opponents of President Mohamed Mursi and his Muslim Brotherhood allies had gathered in Tahrir Square -- there to revive the demands of a revolution that they say has been betrayed by the Islamists.<br/> <br />The square was calm by daybreak, following early morning battles between police and protesters.<br/> <br />But by mid-day, plumes of teargas fired by the police filled the air.<br/> <br />Egypt's Health Ministry said 16 people had been wounded in the clashes so far.<br/> <br />The anniversary will once again showcase the divide between Egypt's Islamists and their secular opponents.
