The Russian ambassador to Ireland Yuri Filatov has accused the Ukrainian government of using "infamous images and fakes about Mariupol".
The city has been besieged by the Russian military since the beginning of March.
Independent observers say large parts of the city have been levelled by Russian shelling and a major humanitarian crisis is apparent for 160,000 people who are trapped there without food, water, shelter or electricity.
Writing a blog on the Telegram website, Mr Filatov accused Ukrainian "neo-Nazis" of using civilians as human shields in the city. He also accused the western media of ignoring shelling of civilians in the so-called Donetsk People's Republic, which is only recognised by Russia.
Earlier this week, the Irish Government announced the expulsion of four Russian diplomats from its embassy in Dublin alleging that they were engaged in espionage.
The US State Department has said it could find no evidence of the Ukrainian army using civilians as human shields. "These types of reports about using civilians as human shield are commonly used in Russian disinformation," a US official said in March.
The ambassador alleged that images of the aftermath of a Ukrainian missile strike in Donetsk which killed 20 civilians appeared in the western media as the aftermath of a Russian strike on the Ukrainian city of Lviv.
Special military operation
Mr Filatov acknowledged that the "special military operation" has been a "dramatic, traumatic period for many Ukrainians", but the suffering of Russian speaking people in the east of Ukraine has been going on since 2014.
Ukraine states that Russia fomented the armed conflict in the Donbass region which has led to the deaths of 14,000 people over the last eight years. Ukraine further alleges Russian troops have been operating in the Donbass since 2014 in order to destabilise the country further.
"It does not fit into the narrative, propagated in Europe, it is being suppressed in the media," Mr Filatov wrote. "There are a lot of hard facts that need to be addressed to make a fair judgement of what has been going on in Ukraine."
Mr Filatov alleged that the government which took over in Ukraine after the Maidan Revolution of 2014 was one composed of “Neo-Nazi and right-wing groups and parties”.
He claimed Ukrainian president Volodymyr Zelenskiy, who is Jewish, co-operated with neo-Nazis when he came to power in 2019. Far right parties got just 2.3 per cent of the vote in the election which brought him to power.
Mr Filatov repeated the assertion made by Russian president Vladimir Putin that the Ukrainian government was planning an offensive operation for the breakaway Donbass region in March.
"In order to prevent the genocide and to deny the Kiev regime any ability to inflict any further suffering on the people of Donbass, the decision was made to start a special military operation in Ukraine," Mr Filatov wrote.
Russian embassy
Mr Filatov alleged earlier this month in a Russian television interview that protesters had been “rough and really aggressive” at the country’s embassy in Dublin.
In an interview with the state-owned Russia 24 television station, Mr Filatov said the situation in Ireland is "frankly difficult", and he accused the country of being to the forefront of "anti-Russian events" in the European Union.
Blaming the Irish media for portraying an “absolutely tendentious picture” of the Ukraine invasion, the ambassador told Russian viewers that the Irish public is hostile to “Russia and everything Russian”.
