One Ukrainian state security officer was killed and five others were wounded on the side of government forces in an "anti-terrorist" operation on Sunday against pro-Russian separatist militants in a city in the east,
the interior minister said.
On the side of the separatists there had been an "unidentifiable number" of casualties during the operation in the town of Slaviansk, the minister, Arsen Avakov, said on his Facebook page.
"There were dead and wounded on both sides," Avakov said. About 1,000 people were giving support to the separatists, he added.
(Reporting by Natalia Zinets; Writing By Richard Balmforth)