-Russia's Novaya Gazeta newspaper, whose editor Dmitry Muratov was a co-winner of last year's Nobel Peace Prize, said on Monday it was suspending its online and print activities until the end of Russia's "special operation" in Ukraine.
The investigative paper, which has already removed material from its website on Russia's military action in Ukraine to comply with a new media law, said it had received another warning from state communications regulator Roskomnadzor on Monday about its reporting, prompting it to pause operations.
"We are suspending the publication of the newspaper on our website, social media networks and in print until the end of the 'special operation on Ukraine's territory'," the paper wrote on its website.
In a separate message to readers, Muratov and his reporters said the decision to halt their activities had been difficult but necessary.
"There is no other choice," the note said. "For us, and I know, for you, it's an awful and difficult decision."
Roskomnadzor did not immediately respond to a request for comment. In comments published by Russian news agencies, the regulator said it had issued Novaya Gazeta a second warning for failing to properly identify an organisation deemed a "foreign agent" by the authorities in its publications.
Pressure against liberal Russia media outlets has mounted since Moscow sent troops into Ukraine last month, with most mainstream media and state-controlled organisations sticking closely to the language used by the Kremlin to describe the conflict.
Novaya Gazeta's announcement follows the closure this month of radio station Ekho Moskvy, which was one of the few remaining liberal voices in the Russian media. Authorities have also blocked the websites of several outlets, including the BBC, Voice of America and Radio Free Europe/Radio Liberty.
On Monday the justice ministry added Germany's Deutsche Welle to a list of media organisations it has labelled as foreign agents.
Readers of Novaya Gazeta and anti-Kremlin activists voiced their regret that the paper could no longer operate in the current Russian media environment.
"I would really like Roskomnadzor to be the one to halt its work," the team of jailed political activist Andrei Pivovarov wrote on Twitter.
Established after the breakup of the Soviet Union, Novaya Gazeta and its reporters have for years been subjected to intimidation and attacks over investigations into rights violations and corruption.
Muratov said on being named co-winner of the Nobel Prize last October that he dedicated it to the memory of six of his paper's journalists who had been murdered for their work.