Moscow called Wednesday for the release of a Russian journalist detained in Ukraine for treason, condemning Kiev authorities for what it said was a repressive policy against the media.
"Russia will do everything to ensure its citizen is freed, and to prevent other journalists finding themselves in similar situations, whether they are Russian citizens or work for Russian media" foreign ministry spokeswoman Maria Zakharova told a press briefing.
Kyrylo Vyshynsky, a dual Ukrainian-Russian national who works for Russian state-run news agency RIA Novosti, was detained in Kiev on Tuesday where officials said he would be charged with treason for his "subversive" reporting to justify Moscow's 2014 annexation of Crimea.
They also said Vyshynsky later collaborated with separatist groups in eastern Ukraine, where a conflict that broke out following Crimea's seizure has cost some 10,000 lives.
RIA Novosti's offices in Kiev were raided on Tuesday by Ukrainian authorities and searched.
Vyshynsky has been transferred to the southern city of Kherson, where he is expected to appear in court of Thursday, said his lawyer Andriy Domansky.
The journalist "considers what happened to him as a provocation, persecution. He doesn't admit what they alleged against him," Domansky told AFP.
Zakharova accused Ukrainian authorities of a "repressive" policy against the media and expressed Russia's "indignation at the brutal violations of the freedom of the press in Ukraine".
Vyshynsky's arrest came just hours before Russian President Vladimir Putin opened a bridge providing the first direct road connection from southern Russia to the Crimean peninsula.
The Kremlin, which had immediately condemned the journalist's arrest as "outrageous and scandalous", reiterated on Wednesday that Russia would respond.
However Kremlin spokesman Dmitry Peskov indicated Ukrainian journalists working in Russia had nothing to fear.
"During all these difficult years Russia has never constrained your professional activities... Unfortunately our journalists working in Ukraine can't claim such treatment," Peskov told a press briefing.
Vyshynsky, 51, worked for several Ukrainian media outlets before becoming a correspondent for Russia's state television channel Rossiya for several years. He later joined RIA Novosti and received Russian nationality in 2015.
Both the EU and United States have said that while Ukraine has the right to protect its national security, it must respect human and legal rights.
"The EU attaches the highest importance to the freedom of expression and of the media," a spokesman told AFP.
But national security measures "must be done in full respect of fundamental rights and freedoms, including the European Convention for Human Rights," added the spokesman.
US State Department spokeswoman Heather Nauert said on Tuesday that a lot of countries have concerns about the reach of Russian propaganda, but that "the arrests of journalists or searches taken of media outlets, if that is done, it has to be done in accordance with the law."
Meanwhile the Council of Europe said it "is concerned about the implications that repeated detentions of journalists may have for the situation with media freedom in Ukraine" and would follow the situation closely.
Kyrylo Vyshynsky, 51, is a Ukrainian-Russian national who works for Russia's state-run news agency RIA Novosti