A pro-Russian separatist guards a checkpoint near the Ukrainian village of Rozsypne in the Donetsk region Monday. The Ukrainian government appeared to be readying an assault on Donetsk, which is held by separatists. (Sergei Karpukhin/Reuters) KIEV, Ukraine — The Ukrainian military on Monday appeared to be readying a long-awaited major assault on the rebel stronghold of Donetsk, warning civilians to leave as troops tightened their ring around the city amid heavy fighting. Extra evacuation corridors were set up for cars bearing white flags, said Andriy Lysenko, a military spokesman. The Donetsk city government posted the corridor routes on its Web page and noted: “As practice shows, such messages are distributed before the start of active combat operations.” Lysenko also announced that troops had taken the town of Yasynuvata, home to a key railway control center between Donetsk and Luhansk. The military has almost encircled the two large cities, where […]