Washington (AFP) - CNN said Thursday a Ukrainian journalist working for the US news channel had been abducted this week by pro-Russian separatists, and appealed for his release.
On its website, CNN said journalist Anton Skiba was taken on Tuesday by armed men from the self-declared Donetsk People's Republic.
Skiba had been working as a freelancer with a CNN crew covering the crisis in Ukraine.
CNN said it did not report the abduction at the time while making efforts to obtain his release. But since those efforts failed, CNN said it was publicly appealing for Skiba's release.
The New York-based Committee to Protect Journalists said Skiba was among at least two journalists abducted after the self-declared Donetsk People's Republic banned the news media from the conflict area. Two others are believed missing.
"Abductions and detentions of journalists and other violations of press freedom are happening at dizzying speed in eastern Ukraine," CPJ's Nina Ognianova said.
"We call on all sides in the conflict to immediately release any journalists in their custody and halt all attempts to censor, obstruct, and intimidate the media."
The US State Department also called for the journalist to be freed.
"We strongly condemn the kidnapping of Ukrainian journalist Anton Skiba by Russian-backed separatists," spokeswoman Marie Harf said.
"We demand his immediate release, along with the other hostages I believe they hold."
Harf added that "we are, of course, concerned for the safety of all journalists and all sides -- all of them -- must permit the media to perform its very important function."
Ukrainian forces have laid siege to the rebel strongholds of Donetsk and Lugansk in southeast Ukraine, capturing some villages and towns in recent days.
Russian President Vladimir Putin is accused by Kiev and the West of arming the rebels in the region where Malaysia Airlines Flight 17 was downed last week.