KIEV, March 10 - A pro-Russian force opened fire in seizing a Ukrainian military base in Crimea on Monday and NATO announced reconnaissance flights along its eastern frontiers as confrontation around the Black Sea peninsula showed no sign of easing, Reuters reported.

Ukrainian activists trying to cross into Crimea to show solidarity with opponents of last week's Russian military takeover there said they were halted by men in uniforms of the now outlawed riot police. One of these fired at close range, hitting a man in the chest, apparently with rubber bullets.