South Sudanese fleeing an attack on the town of Rank, on Saturday. The United Nations says when rebels seized the town of Bentiu, south of Rank, earlier this month, hundreds became victims of ethnically targeted killings. Mohamed Nureldin Abdallah/Reuters/Landov hide caption

itoggle caption Mohamed Nureldin Abdallah/Reuters/Landov

Hostages being held at the U.S. Embassy in Tehran in November 1979. Iran's choice for U.N. ambassador, Hamid Aboutalebi, has acknowledged that he was an interpreter for the student group that seized the compound. AP hide caption

itoggle caption AP

Russia has vetoed a U.N. Security Council resolution that would invalidate Sunday's referendum in Crimea. In Moscow, demonstrators and military veterans march in support of the Kremlin Saturday; nearby, a large march was held to protest Russia's policies. Alexander Zemlianichenko/AP hide caption

itoggle caption Alexander Zemlianichenko/AP

Haitians protest against United Nations peacekeepers in Port-au-Prince in 2010. Hector Retamal/AFP/Getty Images hide caption

itoggle caption Hector Retamal/AFP/Getty Images