The incident came days after Ukrainian President Petro Poroshenko announced a unilateral cease-fire in the battle against pro-Russian separatists. His overture for peace was approved by Russian President Vladimir Putin, along with several leaders of the anti-government movement who have led unrest in Ukraine's Luhansk and Donetsk provinces.
Poroshenko's cease-fire proposal expires June 27, and includes the closing of the Ukraine-Russia border and constitutional modifications to allow more autonomy to provinces.
Notable deaths of 2014 [PHOTOS]
China snares 180 fugitives in graft crackdown