On Sunday, UN Secretary-General Antonio Guterres expressed “deep horror” at photographs of dead civilians in the Ukrainian village of Bucha and asked for an independent investigation that “leads to effective accountability.”

Guterres made his remarks on Twitter a day after witnesses and officials said that Russian troops killed around 300 civilians as they retreated from the town near Kyiv.

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“I am deeply shocked by the images of civilians killed in Bucha, Ukraine,” Guterres expressed shock, echoing Western politicians.

“It is essential that an independent investigation leads to effective accountability,” he said.

The Russian defence ministry denied that Russian forces killed civilians in Bucha, calling the videos and photos of bodies “yet another provocation” by the Ukrainian government.

After seeing images of 20 dead civilians scattered on the streets of Bucha, Ukrainian President Volodymyr Zelensky called Russia’s attacks “genocide.”

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“Indeed. This is genocide,” When asked if Russia was waging a full-fledged genocide in Ukraine, Zelensky remarked on CBS News on Sunday.

“This is happening in the Europe of the 21st century. So, this is the torture of the whole nation,” he addressed the audience.

On Sunday, Bucha, a city northwest of Kyiv, was the target of one of Russia’s most heinous attacks. According to photographs released by AFP, around 20 civilian men’s corpses were discovered spread on the streets following a “scale-back” of Russian soldiers.

Anatoliy Fedoruk, the mayor of Bucha, stated that Russian forces treated the dead citizens in a harsh and inhumane manner.

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“Corpses of executed people still line the Yabluska street in Bucha. Their hands are tied behind their backs with white ‘civilian’ rags, they were shot in the back of their heads. So you can imagine what kind of lawlessness they perpetrated here,” Fedoruk confirmed to Reuters.

The atrocity has sparked outrage around the world, with Western leaders calling for war crimes investigations and increased sanctions against Russia.