The Ukrainian government has promised extra security measures to make sure next Sunday’s presidential election goes ahead in the east of the country.
It says it has information on separatist plans to disrupt the elections, with a number of reports of polling staff being kidnapped.
In Kyiv the prime minister Arseniy Yatsenyuk said the presidential ballot was top priority.
“First, we must have a legally elected President of Ukraine. Second, we will ensure everyone has equal opportunities to participate in the election process. Third, any attempt by terrorists in Donetsk and Luhansk to wreck the presidential election across the whole of Ukraine are doomed to fail,” he said.
Armed pro-Russian separatists have continued to stop cars at checkpoints in parts of eastern Ukraine.
Pro-separatists say they have already made their choice clear when they voted for independence from the rest of the country, setting up self-declared “republics”.
“We had a referendum, we voted. Kyiv does not recognize our vote, our opinion. So this is the way they try to persuade us,” said one resident of Slovyansk.
There were reports of more violence on Monday.
The Ukrainian defence ministry says one soldier was killed and others injured by shelling near Slovyansk.
Elsewhere it said 50 separatists attacked an army checkpoint, with one rebel being killed and several wounded