A member of the Special Monitoring Mission of the Organization for Security and Cooperation in Europe was killed in a road accident in Kramatorsk in the Donetsk region on January 18, the OSCE said.
Vitalie Zara was a citizen of Moldova who had been working for the Luhansk Monitoring Team since July 2015, serving in Sievierodonetsk, Luhansk, and Kadiivka, the organization said in a posting on Facebook on January 19.
Zara was traveling in a taxi in Kramatorsk when the car accident took place. He died at the scene, Russian news agency Interfax reported.
"He is remembered as a trusted, hard-working friend and colleague, always with a smile, and will be missed and mourned," the OSCE said. "Our thoughts and prayers are with his family."
Kurt Volker, the special U.S. envoy for Ukraine, also offered "condolences to the family, friends, and colleagues of Vitalie Zara" on Twitter.
It was the second death of an OSCE monitor in eastern Ukraine in the last year. An American observer was killed last April when the car he was traveling in drove over a land mine.
With reporting by Interfax