Remains of mortar shells are seen by a destroyed Ukrainian army mobile mortar truck in the eastern Ukrainian village of Oktyabrskoe May 14, 2014. Pro-Russian separatists ambushed Ukrainian troops on May 13, killing seven in the heaviest loss of life for government forces in a single clash since Kiev sent soldiers to put down a rebellion in the country’s east. REUTERS/Yannis Behrakis (UKRAINE – Tags: POLITICS CIVIL UNREST CONFLICT)