NEW YORK -- Vice News reporter Simon Ostrovsky, who has been aggressively covering the conflict in Crimea and Ukraine over the past month, is currently being held by pro-Russia separatists in Eastern Ukraine, according to a Russian news outlet.
Gazeta.Ru reported that Ostrovsky was taken "hostage" by a militia. The Russian outlet attributed the information to Vyacheslav Ponomarev, the "People's Mayor" of the Slovyansk, a Ukrainian town now under the control of pro-Russia separatists.
Douglas Herbert, international affairs editor at France 24, tweeted Tuesday that the "self-proclaimed" mayor confirmed "Ostrovsky "is being held by separatists occupying building of Ukrainian security services."
Vice News did not confirm specifics of reports, but acknowledged that the news organization is trying to ensure Ostrovsky's safety.
"Vice is aware of the situation and is in contact with the United States State Department and other appropriate government authorities to secure the safety and security of our friend and colleague, Simon Ostrovsky," a spokesman said in a statement to HuffPost.
Ostrovsky was last tweeting Monday from Ponomarev's press conference.
Nina Ognianova, the Europe and Central Asia program coordinator for the Committee to Protect Journalists, called Tuesday night for Ostrovsky to be released and for those holding him to "stop detaining, harassing, and obstructing journalists reporting on the ongoing crisis in eastern Ukraine.”
“If Vyacheslav Ponomaryov and his associates aspire to gain legitimacy, detaining journalists is counterproductive,” Ognianova said.
Ostrovsky, who who has previously reported for AFP, BBC's "Newsnight" and Al Jazeera English, has gained a following online over the past six weeks as a result of his compelling, first-person video dispatches from the conflict. He's also made several appearances on CNN and MSNBC.
Last month, Ostrovsky was briefly detained at a Russian checkpoint by members of the Berkut, a disbanded Ukrainian police force.
In a March interview with HuffPost, Ostrovsky said that Vice News isn't telling different stories than other correspondents. Rather, he said, "we're just telling them in a different way."
"I'm sort of looking at it in terms of what I can see, where I go, instead of trying to say everything that's happening here in one report," Ostrovsky said. "I just try to tell what it's like on the ground from my own perspective, from having been there and seen what I've seen."
This post has been updated Wednesday morning with the Committee to Protect Journalists statement and new information.