Authorities in Ukraine say they have found what “looks exactly like war crimes” after the bodies of scores of civilians and mass graves were found in the towns of Bucha, Irpin and Hostomel near the capital.

Ukrainian prosecutors said they found 410 bodies in towns near Kyiv, and 140 bodies had been examined on Sunday. Russia denied allegations that its forces had killed civilians as it retreated from war-torn areas of the country.

Satellite images from Bucha appear to show an approximately 45ft-long trench dug into the grounds of a church where a mass grave has been identified.

World leaders condemned the killings and called for independent investigations. French president Emmanuel Macron, UN secretary general António Guterres, German chancellor Olaf Scholz, British prime minister Boris Johnson and US ambassador to the UN Linda Thomas-Greenfield all publicly condemned Russia’s actions.

The US secretary of state, Antony Blinken, described the killings as “a punch to the gut” and joined western allies in vowing to document the atrocities to hold the perpetrators to account.

Russia described the situation in Bucha as a “provocation” by Ukraine intended to disrupt peace talks. The Kremlin’s foreign ministry said Russia was seeking a UN security council meeting on the matter. Its defence ministry described the photos and videos as “another staged performance by the Kyiv regime”. Dmitry Polyansky, Russia’s UN security council deputy representative, tweeted on Sunday: “In the light of heinous provocation of Ukrainian radicals in Bucha Russia requested a meeting of UN Security Council on Monday April 4.”

Ukraine’s president Volodymyr Zelenskiy condemned Russian forces as “murderers”, “torturers” and “rapists” after the killings came to light . “How did they also become butchers? … They killed deliberately and with pleasure,” he said in a national address late on Sunday. He vowed to investigate and prosecute all Russian “crimes” in Ukraine.

Zelenskiy also criticised the west’s “policy of concessions to Russia” in the lead up to the war. Describing Ukraine’s past pursuit of Nato membership: “They thought that by refusing Ukraine, they would be able to appease Russia, to convince it to respect Ukraine and live normally next to us … I invite Mrs Merkel and Mr Sarkozy to visit Bucha and see what the policy of concessions to Russia has led to in 14 years. To see with their own eyes the tortured Ukrainian men and women.”

Russian forces continued their attacks on other Ukraine cities. Seven people died and 34 were wounded after a residential area in Kharkiv was struck on Sunday, local prosecutors said.

At least 70% of Chernihiv has been destroyed by Russian forces, the city’s mayor said on Sunday. Vladyslav Atroshenko said the “consequences” of the attacks were severe and mirrored those of other badly damaged cities in Ukraine such as Bucha and Mariupol.

The capture of Mariupol is a “key objective” of the Russian invasion, UK’s ministry of defence said as heavy fighting continues in the southeastern city.

Russian missiles struck “critical infrastructure”, most likely a fuel depot, near Ukraine’s southern port of Odesa in the early hours of Sunday but there were no casualties, officials in the city said.

The European Union should consider a ban on gas imports from Russia, German defence minister Christine Lambrecht has said.

The huge scale of sexual violence endured by women and girls in Ukraine has begun to emerge as victims recount the abuse they have suffered at the hands of Russian soldiers.