ROUGH CUT - NO REPORTER NARRATION

European military observers held captive in Slaviansk in eastern Ukraine were released on Saturday, the town's pro-Russian separatist leader said, characterising the move as voluntary and made to coincide with his birthday.

Vyacheslav Ponomaryov said 12 people had been freed in total, including Europeans and Ukrainians.

Eight observers who were in Ukraine under the auspices of security watchdog the Organization for Security and Cooperation in Europe (OSCE) were seized last week by separatists who said they had found a spy with them. They later released one on medical grounds.

It was not clear who else was among those released, but the group had been accompanied by at least one translator.

Ponomaryov said Russian envoy Vladimir Lukin, who arrived in eastern Ukraine on Friday, had helped negotiate their release.

Kiev and the West had criticised Moscow for failing to help with the captives' release, saying Russian offic