Anti-government protesters display tear gas canisters used by the police during clashes at Altamira square in Caracas March 3, 2014. Jailed Venezuelan opposition leader Leopoldo Lopez urged sympathizers on Monday to maintain street protests against President Nicolas Maduro as the country's foreign minister prepared to meet the United Nations Secretary General. REUTERS/Tomas Bravo (VENEZUELA - Tags: POLITICS CIVIL UNREST)