Moldovan police said on Sunday they have foiled a plot by groups of Russia-backed actors who were specially trained to cause mass unrest during a protest against the country’s new pro-Western government.

The head of Moldova’s police, Viorel Cernauteanu, said in a news conference that an undercover agent had infiltrated groups of “diversionists,” some Russian citizens, who had been promised money to organize “mass disorder” to destabilize Moldova during a protest in the capital, Chisinau.

Seven people were detained, he said.

Separately, police said they arrested 54 protesters on Sunday, including 21 minors, who exhibited “questionable behaviour” or were found to be carrying prohibited items, including at least one knife.

The protest on Sunday is one of several held in recent weeks organized by a group calling itself Movement for the People, which is backed by Moldova’s Russia-friendly Shor Party, which holds six seats in the country’s 101-seat legislature.

The demonstrators are demanding the government fully cover the costs of winter energy bills and to “not involve the country in war”.

They have repeatedly called on President Maia Sandu to step down.

Police said that four bomb threats on Sunday, including one at the capital’s international airport, had been registered, which they called “an ongoing part of the destabilization measures” against Moldova, a former Soviet republic with a population of about 2.6 million.

Moldova’s border police also said 182 foreign nationals in the last week have been denied entry into Moldova, including a “possible representative” of Russia’s Wagner Group, the private military company that is fighting in Ukraine, Moldova’s war-torn neighbor.

The police announcement omes just days after US intelligence officials said they have determined that actors with ties to Russian intelligence are planning to use protests in Moldova, a European Union candidate since last June, as a basis to foment an insurrection against the country’s government.

On Saturday, Moldova’s national anti-corruption agency said that it has seized more than 220,000 euros (£202,000) during searches in a case of alleged illegal financing of the Shor Party by an organised criminal group.

The agency said that car searches of “couriers” for the Shor Party discovered the money stuffed into envelopes and bags in various currencies, and that it was earmarked to “pay for the transport and remunerate people who come to the protests organized by the party”.

The Shor Party’s leader, Ilan Shor, is a Moldovan oligarch currently in exile in Israel.

Shor who is named on a US State Department sanctions list as working for Russian interests. The UK also added Shor to a sanctions list in December.

Cristian Cantir, a Moldovan associate professor of international relations at Oakland University, says that while it’s difficult to determine how the alleged plans to topple Moldova’s government would play out, “Russia has always sought to undermine pro-European governments”.

“I think the concerns are legitimate, it’s difficult to tell what the exact nature of the threat is and how dangerous some of these groups might be, but it’s absolutely a realistic concern,” he said.

The Shor Party also organised a series of anti-government protests last autumn, when Moldova’s government asked the country’s Constitutional Court to declare the Shor Party illegal, in a case that is ongoing.

Around the same time, anti-corruption prosecutors also alleged that the protests were partly financed with Russian money.

Last week, authorities in Moldova’s breakaway region of Transnistria, which has close ties to Moscow and hosts Russian troops, claimed it had thwarted an assassination attempt on its president allegedly organised by Ukraine’s national security service, the SBU, but did not provide evidence.

The SBU rejected the allegation, saying it “should be considered exclusively as a provocation orchestrated by the Kremlin”.