There has been fresh shelling near Donetsk airport in eastern Ukraine, raising fears that a recently agreed ceasefire may collapse.
The truce held for much of Saturday but shelling in Mariupol, which killed one woman, was followed by the Donetsk airport blasts early on Sunday.
The two cities then turned quiet, with no reports of clashes overnight.
Fighting in the east has killed some 2,600 people since April. The truce and roadmap to peace were agreed on Friday.
On Sunday, Ukrainian security official Volodymyr Poliovyi said 864 Ukrainian soldiers had been killed since the conflict began.
Russia has repeatedly denied accusations by Ukraine and the West that it has been sending troops into Ukraine’s eastern Donetsk and Luhansk regions to help the rebels, who want to establish an independent state.
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Before the ceasefire was agreed in Minsk, Belarus, on Friday, the separatists had been advancing on both Donetsk airport and Mariupol, a key city on the route to Crimea, which was annexed by Russia in March.
An OSCE team said that most of the firing in Donetsk hit targets outside the airport
We have just been at Donetsk airport which has in recent weeks been the focus of the fighting between Ukrainian forces and separatist rebels, with Ukrainian troops inside the main building there holding the airport.
We have heard a lot of mortars being fired, both into the airport area and outgoing as well. We also met an observer team from the Organization for Security and Co-operation in Europe (OSCE).
It said most of the firing was outgoing from the airport, ie from Ukrainian troops. It said the firing had caused some fires in villages nearby but stressed that, although a violation of the ceasefire, the fighting at Donetsk airport was not sufficient to actually make the ceasefire collapse. Agency report
