(Updates with Krat speaking to reporters, pvs KIEV)
By Aleksandar Vasovic
SLAVIANSK, Ukraine, April 21 (Reuters) - A Ukrainian journalist being held by pro-Russian separatists in eastern Ukraine was brought out by her captors on Monday and told reporters she was being questioned but not mistreated.
Irma Krat, 29, emerged briefly from the Ukrainian state security service building in Slaviansk, where she is held, to tell journalists, a day after she was detained: "Conditions are OK. It is a bit cold, but they are giving me food, water."
She said she was not aware of a second Ukrainian journalist reported to have been held there since last week.
A member of the local militia holding her said Krat, who runs an online news site, was suspected of involvement in the mistreatment of riot policemen and a Russian journalist who were seized by activists during the "Euromaidan" protests in Kiev that led to the fall of the Moscow-backed president in February.
"We are checking that information," said the man, who did not give his name. "If it turns out to be true, she will be handed over to the police." Krat herself said she was not being "accused" but was being asked about her activities locally.
After a few minutes, a militant blindfolded Krat and led her back into the building.
Ukrainian journalists have also said that another reporter, freelancer Serhiy Lefter, 22, has not been heard of since last week, when acquaintances believed he was held in Slaviansk. The activists have not commented on his whereabouts.
Other journalists have been held for up to a few hours by armed men who took over public buildings in Slaviansk nine days ago as part of a wider protest movement in Russian-speaking eastern Ukraine.
They are demanding a referendum that could lead to the area following Crimea into annexation by Moscow.
Local media which reported that three foreign reporters had been detained on Monday, later said they had all been released.
Also on Monday in Slaviansk, separatists said they were releasing about a dozen Ukrainian servicemen taken prisoner in nearby Kramatorsk last week, saying they would be put on a train to return them to their families.
The men, in blue uniforms, were marched away from the security building, watched by journalists. It was not clear which unit they were from.
The servicemen from a now-disbanded paratroop unit were taken last week along with several of their armoured vehicles after their military convoy was commandeered by separatists and civilian protesters in Kramatorsk.
(Reporting by Aleksandar Vasovic in Slaviank and Natalia Zinets and Alastair Macdonald in Kiev; Editing by Richard Balmforth; Writing by Alastair Macdonald)