The Ukrainian military said it had recorded 12 ceasefire violations by pro-Russian separatists in east Ukraine on Saturday morning after 66 cases over the previous 24 hours.
Separatists opened fire on more than 20 settlements, using heavy artillery, which have been prohibited by Minsk agreements, the military said on its Facebook page.
Incidents of shelling across the line dividing government forces and separatists increased sharply this week, in what the Ukrainian government called a provocation. It strongly denied suggestions by Russia that Kyiv could launch an offensive in eastern Ukraine.