After 10 Ukrainian military servicemen were freed from captivity on Friday, another 255 are still being held by militants, Ukrainian parliamentarian Iryna Heraschenko of the Petro Poroshenko Bloc said on Facebook on Friday.

"As many as 255 Ukrainians remain in captivity, including 11 in Russian prisons. We are continuing to work until we have all of our heroes freed," Heraschenko said.

"About 30 Ukrainians have been freed over the two months of work of the Minsk groups," she said.

The servicemen released on Friday had remained in captivity for 6 to 9 months, and their exchange required "hard work," Heraschenko said. "The president, the SBU [the Ukrainian Security Service], the Defense Ministry, and our group on humanitarian issues […] are doing everything that is in our powers. This is not easy, and this involves talks that are far from always being pleasant. But freedom of our guys is above all," she said.