Russia on Saturday promised it would respond harshly to what it said was Poland's illegal seizure of its embassy school in Warsaw, an act it called a flagrant violation of the Vienna Convention on diplomatic relations.
Polish state-run news channel TVP Info had earlier reported that police had shown up outside the Russian embassy school on Kieleckiej Street in Warsaw on Saturday morning.
When asked about the incident, a Polish foreign ministry spokesman told Reuters the building housing the embassy school belonged to the Polish state.
Russia's foreign ministry said in a statement that the Polish authorities had burst onto the embassy school's grounds with the aim of seizing it.
"We regard this latest hostile act by the Polish authorities as a blatant violation of the 1961 Vienna Convention on Diplomatic Relations and as an encroachment on Russian diplomatic property in Poland," the ministry said.
"Such an insolent step by Warsaw, which goes beyond the framework of civilized inter-state relations, will not remain without a harsh reaction and consequences for the Polish authorities and Polish interests in Russia," it said.
Poland acting legally but Russia has right to protest - Polish foreign ministry spokesman
Lukasz Jasina, a Polish foreign ministry spokesman, told Reuters that it was Russia's right to protest but that Poland was acting within the law.
"Our opinion, which has been confirmed by the courts, is that this property belongs to the Polish state and was taken by Russia illegally," he said.
Sergei Andreyev, Moscow's ambassador to Poland, had earlier told Russian state news agencies that the building housing the embassy school was a diplomatic one that Polish authorities had no right to seize.
"Our opinion, which has been confirmed by the courts, is that this property belongs to the Polish state and was taken by Russia illegally."
Lukasz Jasina
The two countries' already fraught relations have soured further over the war in Ukraine with Warsaw positioning itself as one of Kyiv's staunchest allies, playing a leading role in persuading allies to provide it with heavy weaponry.
Andreyev, the Russian ambassador, said earlier this week that Polish prosecutors had seized significant amounts of money from the frozen bank accounts of the Russian embassy and trade mission.
In March 2022, Poland said it was expelling 45 Russian diplomats suspected of working for Moscow's intelligence services.