Novaya Gazeta, one of Russia’s leading independent newspapers, is suspending operations until the end of the war in Ukraine, the daily said Monday. The newspaper, whose editor Dmitry Muratov won the Nobel Peace Prize last year, said it had taken the decision after receiving multiple warnings of legal action from the government’s Roskomnadzor censorship agency.

This came a day after Russia’s communications watchdog asked the media to refrain from reporting a 90-minute Zoom interview of Ukrainian president Volodymyr Zelenskyy by four prominent journalists and said it had started a probe into the outlets which had interviewed the leader.

The official reason for the warnings to the newspaper was its alleged failure to properly label “foreign agents” in its articles, but the warnings are widely considered to be in retaliation to Novaya Gazeta’s coverage of the invasion, according to Moscow Times.

“We received another warning from Roskomnadzor. After that, we are ceasing covering both online and in print until the end of the ‘special operation on the territory of Ukraine’,” the paper said in a Telegram post.

Russia has ramped up its crackdown on independent media and civil society since it launched its invasion of Ukraine in February. Outlets are banned from reporting anything except official government sources, with editors and outlets potentially liable for up to 15 years in prison for breaking the new rules, according to Moscow Times. Most Russian independent outlets have been forced into exile, but Novaya Gazeta initially tried to continue reporting inside the country, drawing attention to the Kremlin’s attack on media freedom by publishing blank pages to represent the information they are not allowed to report.

It is one of Russia’s oldest independent media outlets. Six of its reporters have been killed in assassinations the paper and rights groups say are connected to their reporting into corruption and human rights abuses, particularly in the restive Chechnya region of Russia’s north Caucasus.