The move unleashed deadly strife that led to Yanukovych 's ouster , Ukraine 's loss of Crimea , and a pro-Russia separatist rebellion . Interior minister says militants have attacked police HQ , causing police casualties . Putin says he tried to persuade Poroshenko to resolve crisis through peaceful means . Comment: Poroshenko declares an end to a unilateral cease-fire with pro-Russian separatists .
Interior minister says militants have attacked police HQ , causing police casualties . Putin says he tried to persuade Poroshenko to resolve crisis through peaceful means . Comment: Poroshenko declares an end to a unilateral cease-fire with pro-Russian separatists .