This is reported by Censor.NET citing the State Border Guard Service.
According to the report, the man was heading to the temporarily uncontroled territory of Ukraine. When asked for documents, he hurriedly provided those proving his connection with terrorist organizations. In particular, he showed a certificate issued by the so-called "ministry of state security" of the self-proclaimed republic stating he was a member of the terrorist battalion "Vostok". Also, he turned out to be a priest of the Ukrainian Orthodox Church (Moscow Patriarchate).
Examination is underway.
Related materials: Anti-Terrorist Operation