在乌克兰旨在结束政府军与亲俄分离武装在东部地区激战的停火协议星期六午夜生效后不久，一名乌克兰官员说，星期天凌晨发生一些破坏停火的行动。
乌克兰安全部门首脑瓦连京.纳里瓦伊琴科说，俄罗斯哥萨克人看来对在卢甘斯科地区的迫击炮轰击事件负责，目前正在进行调查。
早些时候，乌克兰总统波罗申科在午夜发表的现场广播讲话中下令乌克兰武装部队实行停火。
按照欧洲斡旋的停火协议，乌克兰政府军和俄罗斯支持的分离反叛武装停火，一旦实现了停火，双方应开始向后撤出重型武器，形成一个地域广阔的缓冲区。
A Ukrainian official has reported cease-fire violations in the early hours of Sunday, shortly after a truce went into effect to end intense fighting in the country's east between Ukrainian forces and pro-Russian separatists.
The head of Ukraine's security service, Valentyn Nalyvaichenko said Russian Cossacks appear to be responsible for mortar shelling in the Luhansk region. He said an investigation is under way.
Earlier, Ukraine's President Petro Poroshenko ordered his forces to comply with a cease-fire that went into effect at midnight.
Under the terms of the European deal brokered in Minsk, Ukrainian forces and Russian-backed separatist rebels were to stop shooting. If that holds, both sides are to begin pulling back their heavy weaponry to form a wide buffer zone.
