WARSAW (Reuters) - Poland is to send a protest note to Russia after it removed a Polish flag at the Katyn cemetery, which commemorates Polish military officers killed by Soviet forces in 1940, the government said on Monday.
An estimated 22,000 officers and intellectuals were killed in Katyn, near Smolensk in western Russia, many trucked in from prison camps, shot in the head from behind, and shoved into mass graves.
After blaming Nazi Germany for the Katyn massacre for decades, the Soviet Union admitted in April 1990 that its forces were responsible, with the killings casting a long shadow over relations between Russia and Poland.
The bodies of more than 4,000 Polish prisoners of war are buried in the cemetery, which is run by the Russian authorities.
On Friday Smolensk mayor Andrei Borisov, published a photo of two masts - one with a Russian flag and one empty with a ladder leaning against it - saying the Polish flag had been removed.
"There can be no Polish flags on Russian memorials! ... I think that the Ministry of Culture of the Russian Federation made the only correct decision - to remove the Polish flag. Katyn is a Russian memorial, it is Russian history," Borisov wrote.
The move further dents relations between the two countries after Poland's leading role opposing the war in Ukraine.
"At this moment a (diplomatic) note is being written, which will be submitted to the Ministry of Foreign Affairs," Polish Deputy Foreign Minister Marcin Przydacz told Polish public radio on Monday.
"We will try to intervene on the political level, but ... I do not have excessive optimism about the actions of the Russian side. The Russian side is rather aggressive in foreign policy," he added.
The Russian Foreign Ministry did not immediately respond to an emailed request for comment.
(Reporting by Anna Koper; Editing by Alison Williams)