Bodies of more than 900 Ukrainian civilians have been found in Kyiv since Russia's withdrawal, according to police.
Earlier this month, Kremlin forces retreated after weeks of trying to breach the defences of the capital city and have since been regathering for attacks in the east.
But on freeing the towns and villages from their occupation, the horrifying alleged war crimes committed by invading soldiers were laid bare.
Andriy Nebytov, the head of Kyiv’s regional police force, said today bodies were left on the streets or given temporary burials.
He said that data indicates 95% died from gunshot wounds.
"Consequently, we understand that under the (Russian) occupation, people were simply executed in the streets," Mr Nebytov said.
More bodies are being found every day, under rubble and in mass graves, he added.
"The most victims were found in Bucha, where there are more than 350 corpses," he said.
A war crimes prosecutor has vowed to catch the unimaginably barbaric Russian troops behind the massacres.
As he watched four more corpses being removed from a mass grave of over 100 dead in stricken Bucha, War Crimes Prosecutor Andrii Turbor told the Mirror: “No matter how long it takes, time does not matter, we will catch those responsible for killing these innocent people.
“This was unimaginable barbarism resulting in the deaths of so many people who were harmless, children, elderly people, women, civilians.
“These people were Ukrainians and I am a Ukrainian - this is a matter of personal respect to do justice for these poor people.
“This morning we found a 75 to 80 year-old woman here. Who can imagine killing such a person? I cannot imagine it.”
It comes after Moscow troops' attacks on civilians in Ukraine were officially declared war crimes in a devastating international report ordered by 45 countries.
Vladimir Putin's forces' attack that killed 300 people sheltering in the Mariupol Theatre was “most likely… an egregious violation” of humanitarian law and “those who ordered or executed it committed a war crime”, the report said.
It also dismissed Russia 's claims that its attack on a maternity hospital in Mariupol last month was “fake news”, saying the attack “must have been deliberate”.
It added: “This attack therefore constitutes a clear violation of international humanitarian law and those responsible for it have committed a war crime”.
The Organisation for Security and Cooperation and Europe (OSCE) interim report ran to nearly 100 pages and said Russian forces have intentionally targeted healthcare sites.
The report only covers the conflict up to April 1, which means atrocities uncovered as Russian forces pulled back from Kyiv in recent weeks have not yet been fully analyse.
Grim evidence of the killing of civilians in Bucha shocked the world, as well as the recent rocket attack on a train station in Kramatorsk where people were trying to flee.
There were “several credible reports” of Russian forces “arresting civilians, including journalists, without any procedure, and ill-treating them by methods that amount to torture. This constitutes a war crime,” the report said.
The report noted there have been “allegations of rapes, including gang rapes, committed by Russian soldiers in many other regions in Ukraine ".
And it said: “Russia is failing to agree to evacuations or is violating such agreements through attacks on those trying to leave.
“Intentionally using starvation of civilians as a method of warfare by depriving them of objects indispensable to their survival… constitutes a war crime.”
The report concludes: “Violations occurred on the Ukrainian as well as on the Russian side.
"The violations committed by the Russian Federation, however, are by far larger in scale and nature.”
