• Horrific images of bodies in streets in towns like Bucha have generated shock and condemnation worldwide.
• Russia denies killing civilians, and without evidence says Ukraine staged the scenes.
Image: BBC
Ukrainian President Volodymyr Zelensky has warned that the worst atrocities committed by Russian troops departing from the north of the country are yet to be discovered.
He said the town of Borodyanka may have suffered more than others.
Horrific images of bodies in streets in towns like Bucha have generated shock and condemnation worldwide.
Russia denies killing civilians, and without evidence says Ukraine staged the scenes.
But the images prompted US President Joe Biden to call for his Russian counterpart Vladimir Putin to be tried for war crimes.
His intervention follows the publication of new satellite photos by the earth observation company Maxar, which show bodies lining Bucha's streets during its occupation by Russian forces.
The Ukrainian government started a war crimes investigation after it said the bodies of 410 civilians had been found in areas around Kyiv.
Some were discovered in mass graves while others had their hands tied and had apparently been shot at close range.
Foreign Minister Dmytro Kuleba told a news conference in Warsaw on Monday that the killings were the "tip of the iceberg" and demanded more severe sanctions against Russia.
In a BBC interview, he cited the desperate situation in the southern town of Mariupol, which has been under Russian bombardment for weeks.
"What we've seen in recent weeks is that Russia is much worse than Isis [the Islamic State group] when it comes to its atrocities and massacres," he said.
In his nightly address to the Ukrainian people, Mr Zelensky said things were done throughout the region north of Kyiv that people had not seen since the Nazi occupation.
"There is already information that the number of victims may be even higher in Borodyanka and some other liberated cities," he said.
Mr Zelensky is due to speak to the United Nations Security Council later on Tuesday, where he is expected to offer more evidence of atrocities.
Several Western nations have expelled Russian diplomats in response to the discovery of the atrocities, and new sanctions against Russia are being discussed.
But Moscow's ambassador to the UN said Russia would present "empirical evidence" to the UN Security Council demonstrating that Western statements on events at Bucha were lies.