Learning from Uncle Sam - to Russia's annoyance, U.S. hones Ukrainian fighting skills

YAVORIV, Ukraine (Reuters) - Tense Ukrainian soldiers with assault rifles creep stealthily around mock houses before bursting in to clear out gunmen, while others practise setting ambushes or infantry assaults, all under the watchful eyes of U.S. Army trainers.

Dotted around the vast, wooded Yavoriv military training area in western Ukraine, soldiers of the U.S. 173rd Airborne Brigade are instructing Ukrainian national guardsmen in techniques designed to help them in the simmering war against pro-Russian separatists hundreds of miles to the east.