About 21 people died following a "full-scale military clash" in the eastern city of Mariupol, Ukraine's interior minister has said.
Writing on his Facebook page, Arsen Avakov said a group of "about 60 terrorists armed with automatic weapons" had tried to storm the town's police headquarters.
He said that an initial "fight" had turned into a "full-scale military clash" involving police and the Ukrainian national guard, leaving "near to 20" pro-Russian separatists and one Ukrainian serviceman dead.
He also insisted there would be no backing down from Ukrainian forces facing armed separatists, saying:
"Our position towards armed terrorists will remain one and the same - shoot to kill."
European Union foreign ministers added 13 people to their visa ban and asset freeze list over Ukraine's crisis.
Well that’s the voting over, and no surprises so far. A ‘Yes’ vote claimed to be 89% in Donetsk, and suddenly Ukraine is no more.
Nearly 90 percent of voters in eastern Ukrainian region voted for self-rule, the head of the separatist election commission said.