In the past week, eastern Ukraine has suffered some of the heaviest fighting seen for a long time. Reports Aljazeera.
Heavy artillery fire, a car bomb explosion and other ceasefire violations coincided with a phone call between US President Donald Trump and Vladimir Putin, his Russian counterpart.
The two leaders discussed how to mend relations between the US and Russia.
US senators and analysts are wondering whether the surge in fighting is the Kremlin testing the water with the new US president.
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Ukrainian government leaders and pro-Russia separatist rebels are blaming each other for the ceasefire violations.
Trump phoned Ukrainian President Petro Poroshenko and promised to restore peace.