Protesters showered the Russian envoy to Poland in a crimson substance as he went to lay flowers on Monday, at the Soviet Military Cemetery in Warsaw to commemorate the 77th anniversary of the triumph over Nazi Germany.

The conflict in Ukraine has placed a pall on Victory Day, when Moscow commemorates the 27 million Soviet citizens who died in World War Two. Poland, which has been a staunch supporter of Ukraine’s fight to Russia’s invasion, has spoken out against any large-scale commemoration.

Video footage posted on Twitter showed the protesters, some with Ukrainian flags, surrounding the Russian delegation and chanting “fascists” before the ambassador was doused in the red substance.

Ambassador Sergey Andreev told reporters he and his team were not seriously hurt in the incident, TASS news agency reported.

“We will make a formal protest,” he said. “When they recommended that we not hold a larger event, we met them halfway, we didn’t aggravate the situation.”

Earlier in the day the words “Kill Putin” were found written in blue and yellow, the colours of the Ukrainian flag, on a monument at the cemetry, private broadcaster TVN24 reported. The writing was later removed.

One protester interviewed by TVN24 said it was good that the ambassador had been covered in red.

“With all our heart we are with Mariupol,” she said, referring to the southeastern Ukrainian city that has been devastated by the war.

More than three million Ukrainians have fled to Poland since the war started on Feb. 24.

Poland, home of the Solidarity trade union that played a key role in bringing down communism in central and eastern Europe, has long had a tense relationship with Russia and is an advocate of tough sanctions against Moscow over its invasion of Ukraine.

Russian President Vladimir Putin sent his troops into Ukraine on what he calls a “special military operation” to demilitarise and “denazify” Ukraine. Ukraine and the West say Putin launched an unprovoked war of aggression.

A Polish foreign ministry spokesman said he had no immediate comment on the incident. A police spokesman could not immediately be reached for comment.