Tensions are escalating in Ukraine following last week's ousting of president Viktor Yanukovych. Weeks of street demonstrations led to Mr Yanukovych leaving the country by helicopter in the middle of the night. Thousands of protestors in west Ukraine fought bloody battles in the capital, Kiev. Scores of people died in the violence, many shot by riot police. The protestors were demanding the resignation of Mr Yanukovych, economic reforms, and closer ties with the European Union. The east of the country did not see the levels of violence witnessed in the capital, largely because most people there voted for Yanukovych and lean more towards Russia than the EU.

The White House has said it no longer considers Mr Yanukovych to be the president of Ukraine. The U.S. Secretary of State John Kerry also warned Russia not to intervene in Ukrainian affairs. A White House spokesman said: "We strongly support Ukraine's territorial integrity and sovereignty." Fears are increasing that Ukraine could break in two as pro-Russian separatists are becoming more active, especially in the autonomous region of Crimea. Armed gunmen wearing Russian military uniforms were reportedly guarding Crimea's main airport on Friday. Ukraine's acting president Oleksander Turchynov warned Russia against "military aggression" after Russia mobilised 150,000 troops near the Ukrainian border.