Ukrainian troops were locked in a “fierce” confrontation with Russian fighters Friday for control of the town of Vuhledar southwest of Donetsk as the two sides battle along the southern front. Both sides claimed success in the small administrative center of apartment blocks surrounded by flat fields, a short distance from the strategic prize of the village of Pavlivka. “The encirclement and subsequent liberation of this city solves many problems,” said Denis Pushilin, the Moscow-appointed leader of the Donetsk region. “Soon, Vuhledar may become a new, very important success for us,” he was quo…