The sound of air raid sirens and loud explosions blared from a loudspeaker, set up by Ukrainian activists, outside the Soviet Military Cemetery in Warsaw this morning.
The activists had gathered to prevent Russia's ambassador to Poland, Sergei Andreyev, from laying a wreath at the cemetery's monument on Victory Day, Russia's annual commemoration of victory over Nazi Germany.
The activists from Euromaidan-Warsaw, a civil society group, hoped to use the occasion to highlight Russia's invasion of Ukraine and the deaths of thousands of Ukrainian civilians.
Last year Mr Andreyev was doused in red paint by Ukrainian anti-war demonstrators at the cemetery.
A large detachment of Polish police was present to prevent any repeat of a confrontation this year.
Instead, Ukrainian activists had set up an art installation at the entrance to the cemetery, which featured crosses with the names of Ukrainian civilians killed since the beginning of the war, and large paper blocks representing damaged Ukrainian cities.

The activists hoped that the Russian ambassador would have to walk through the installation, past the symbolic crosses and hundreds of Ukrainian flags, on his way to lay a wreath at the cemetery's obelisk.
"With this installation, you can [see] the destroyed cities, the destroyed streets, destroyed buildings, destroyed human lives," Victoria Pogrebniak, one of the activists, told RTÉ.
"The propaganda that they are trying to do today about victory is absolutely a farce. They are the ones who restarted fascism again in the 21st century," said Ms Pogrebniak.
Shortly after 11am local time, Mr Andreyev arrived, flanked by his fellow Russian diplomats, and walked about ten metres before stopping just in front of the installation. He appeared to say a few words to the media before returning to his car and leaving with his entourage.
Following the ambassador’s departure, a small group of Polish citizens, some of whom wore the orange and black ribbons, an emblem of today’s Russian armed forces, laid flowers at the Soviet monument.
The small group of mostly elderly Poles was confronted by Ukrainian and Polish protesters standing on the plinth of the monument, holding a banner which read: 'Russia is a terrorist state'.

One female Polish protester shouted that the Poles attempting to lay flowers were "Polish traitors".
Tomasz Jankowski, 33, from the southern Polish town of Mielec, was one of those who attempted to lay flowers to remember the Soviet dead.
He told RTÉ News that he did not believe Russia was at fault for the current war in Ukraine, though said he was against all wars.
More than 21,000 Soviet soldiers, some of whom were Polish, are buried in the cemetery. They died during the Red Army's offensive through Poland against Nazi German forces during 1944 and 1945.
By 1pm local time, Polish police began to pack up. It was clear that Russia’s ambassador was not about to return to lay a wreath.
