A child plays near a Russian soldier, right, while Ukrainian soldiers look on from behind gates as the Russian soldier guards the gate of an Ukrainian infantry base in Perevalne, Ukraine, Tuesday, March 4, 2014. Russian President Vladimir Putin said Moscow reserves the right to use all means to protect Russians in Ukraine as U.S. Secretary of State John Kerry was on his way to Kiev. Tensions remained high in the strategic Ukrainian peninsula of Crimea with troops loyal to Moscow firing warning shots to ward off protesting Ukrainian soldiers. (AP Photo/Darko Vojinovic)