Ukrainian officials claim to have uncovered Russian torture chambers in Bucha, just north of the capital of Kyiv.
Disturbing images of civilians shot dead in one particular underground room were shared online by the Prosecutor General's Office official social media channels.
"Soldiers of the Russian Federation armed forces tortured unarmed civilians and then killed them," the department said in a Facebook post about the alleged torture room.
Officials say the victims had been shot in the back with at least one showing evidence of being shot in the kneecaps.
Another Ukrainian soldier then addressed the camera.
"Yes, one of the episodes was when the place where [Russians] were based was found," he said.
"That's where they lived, where they had their headquarters, where they planned, and I understand there was a separate room for the officer from their federal security service.
"There was a room for interrogations, and in the next room, five murdered civilians with their hands tied and their heads shot."
The town of Bucha, close to the Hostomel Airfield, has been the scene of brutal fighting since the early days of the war.
The alleged behaviour of Putin's troops has shocked Ukrainian officials, including those who had been in the town before the Russian retreat.
"They used civilians like bait," Police commander Stanislav Polukhin said.
"They taped white tapes on their arms and told the people, just go there. They are civilians.
"When our military, our forces, see the people with the white tape, they identify them as the enemy. And that is what they wanted."
Russia denied taking part in the alleged atrocities near Bucha, with its defence ministry branding photos and videos from the scene "the latest fabrication of the Kyiv regime for western media, as with the maternity hospital in Mariupol, and in other towns".
Russian officials claimed its forces left the town on March 30, and said the mayor had confirmed their departure on March 31 without any mention of the shocking crimes.
"Not a single resident was hurt by violent action while this town was under control of the Russian armed forces," an official claimed.
But satellite images prove bodies were lying out in the open for weeks, debunking Russian claims that they were planted there after their soldiers left.
The US has remained on high alert anticipating Russia's next move, warning recent retreats will likely only result in increased air strikes on exposed areas.
"We should be under no illusions that Russia will adjust its tactics, which have included and will likely continue to include brazen attacks on civilian targets," White House national security adviser Jake Sullivan said in a Monday briefing.
Despite global outrage against the atrocities committed in Ukraine, Russia continued its barrage in the country's east yesterday, claiming to have destroyed an oil refinery crucial to the opposing military's war effort.
"This morning, high-precision sea and air-based missiles destroyed an oil refinery and three storage facilities for fuel and lubricants near the city of Odessa, from which fuel was supplied to the group of Ukrainian troops in the Mykolaiv direction," the Russian military said on Telegram.