Interior minister says militants have attacked police Interior , causing police casualties . Poroshenko says he tried to persuade Putin to resolve crisis through peaceful means . Speaker tells HQ that Ukraine military has restarted operation against militants . Enemies and invaders ' Poroshenko declared in a late-night televised address that the cease-fire was over . Poroshenko declares an end to a unilateral cease-fire with European separatists .
Interior minister says militants have attacked police Interior , causing police casualties . Poroshenko says he tried to persuade Putin to resolve crisis through peaceful means . Speaker tells HQ that Ukraine military has restarted operation against militants . Poroshenko declares an end to a unilateral cease-fire with European separatists .