Russian state television reported that five people were killed when gunmen attacked a checkpoint manned by pro-Russian separatists near the eastern Ukrainian city of Slaviansk.
The state-run Rossiya 24 news station, citing its correspondent in Slaviansk, said three of the dead were with the pro-Russian separatists who control Slaviansk, and the other two were from the group that attacked their checkpoint.
Tensions remain high in eastern Ukraine after at least three died in a day of shooting during what was supposed to be an Easter truce.
In an exclusive interview with NBC News, the Ukrainian Prime Minister warns of the dangers of unchecked Russian expansion and aggression.
Russia, the US and the EU say that all sides have agreed to steps to "de-escalate" the crisis in Ukraine at talks in Geneva.