Nine Ukrainian army soldiers have been killed and several dozen injured in the military-operation zone in eastern Ukraine in the past 24 hours, said Andriy Lysenko, a spokesman for the Ukrainian National Security and Defense Council.

"Nine Ukrainian military service members have been killed and 27 have been injured," he said at a briefing in Kyiv on Monday.

"The past 24 hours saw the release of 30 captured Ukrainian military servicemen, 27 of them are members of the Ukrainian Armed Forces, two from the National Guard and one border guard," he said.

Over 1,000 Ukrainian military service men have been freed since the Minsk protocol was signed on September 5, Lysenko also said.