President Vladimir Putin has warned he will cleanse Russia of “scum and traitors” whom he accuses of working covertly for the United States and its allies, as the government steps up pressure on domestic critics of his war against Ukraine.

Facing economic collapse three weeks after the invasion, the Russian leader accused the West of wanting to destroy Russia in a darkly-tinged televised video conference.

“Any people, and particularly the Russian people, will always be able to distinguish patriots from scum and traitors and spit them out like a mosquito that accidentally flew into their mouths,” Putin said.

“I am convinced that this necessary self-cleaning of society will only strengthen our country, our solidarity, cohesion and willingness to face any challenge,” he remarked.

Asked how such a cleanup would work, Kremlin spokesman Dmitry Peskov said Thursday that people “are disappearing from our lives by themselves ,” including quitting their jobs or leaving Russia.

“This is how this purification happens,” he told reporters in a conference call, adding that many people “show themselves to be traitors” in difficult times.

Putin’s threat came two days after a producer from Russia’s state-run Channel One channel interrupted the news with a rare public outcry against the war in Ukraine. Marina Ovsyannikova held up a banner behind the news anchor that read: “They are lying to you.” After she was given a small fine, the speaker of the lower house of Russia’s parliament denounced her protest as “treason” and called for her to be punished “with full rigour.”

Nearly 15,000 people have been detained in anti-war protests in Russia since Putin ordered the invasion on February 24, according to the human rights organization OVD-Info. In a new effort to stifle criticism, Russia this month adopted a tough new media law that threatens prison terms of up to 15 years for spreading “fake news” about its military or calling for sanctions against the country.

Tens of thousands of Russians have fled abroad to escape the deepening crackdown, seeing little future for themselves as sanctions plunge the country into deeper isolation. Many left their homes and careers to seek refuge in countries such as Kyrgyzstan, Georgia, Armenia, Turkey and Israel.