A Ukrainian military spokesman says one Ukrainian serviceman has been killed and five wounded in clashes between government forces and Russian-backed separatists over the past 24 hours.
It was not immediately clear from the report where the serviceman died and under what circumstances.
The casualties occurred despite a cease-fire agreement negotiated in mid-February.
Meanwhile, TASS reports that the Defense Ministry of the self-proclaimed Donetsk People's Republic registered 27 cease-fire violations by the Ukrainian military in the past day.
The figures could not be independently confirmed.
Violence has lessened significantly since the cease-fire was declared, but both sides accuse the other of violations and casualties are reported almost daily.