President Barack Obama called President Vladimir Putin of Russia on Tuesday to address the escalating violence in eastern Ukraine and Russia’s ongoing support for the separatists there. _____________________________________________. Rocket strikes in the eastern Ukrainian city of Kramatorsk on Tuesday hit the headquarters of the military's operation against Russia-backed separatists and residential areas. The Ukrainian National Security and Defense Council says "preliminary data," shows the rebel rocket attacks killed 15 people. This is VOA News. 美国总统贝拉克奥巴马周二致电俄罗斯总统弗拉基米尔普京就乌克兰东部暴力冲突加剧升级以及俄对乌分裂势力的不断支持商议解决方案。________________________________。周二一枚火箭弹击中了位于乌东部城市Kramatorsk的抵抗亲俄分裂武装的军事指挥所和居民区。乌克兰国家安全防卫委员会称初步数据显示反对派火箭袭击已造成15人死亡。以上是VOA新闻。