(NewsNation) — Moscow faced growing accusations of war crimes Monday after Russian ground forces pulled out from areas on the outskirts of Kyiv, revealing streets strewn with corpses of what appeared to be civilians.

The grisly images of battered bodies out in the open or in hastily dug graves led to calls for tougher sanctions against the Kremlin, namely a cutoff of fuel imports from Russia. Germany reacted by expelling 40 Russian diplomats, and Lithuania threw out its Russian ambassador.

Ukrainian President Volodymyr Zelenskyy left the capital, Kyiv, for his first reported trip since the war began nearly six weeks ago to see for himself what he called the “genocide” and “war crimes” in the town of Bucha, the site of some of the horrors.

“Dead people have been found in barrels, basements, strangled, tortured,” said Zelenskyy, who again called on Russia to move quickly to negotiate an end to the war.

President Joe Biden on Monday called for a war crimes trial against Russian President Vladimir Putin and additional sanctions following reported atrocities in Bucha.

“What’s happening in Bucha is outrageous and everyone sees it,” Biden said.

Oleksiy Arestovych, an adviser to President Zelenskyy, said scores of killed civilians were found on the streets of Bucha and the Kyiv suburbs of Irpin and Hostomel in what looked like a “scene from a horror movie.”

Arestovych said some people were shot in the head and had their hands bound, and some bodies showed signs of torture, rape and burning.

U.S. Secretary of State Anthony Blinken called the images “a punch to the gun” and said the U.S. would help in the investigation.

Ukraine’s prosecutor-general says the bodies of 410 civilians have been removed from Kyiv-area towns that were recently retaken from Russian troops.

Iryna Venediktova says on Facebook that the bodies were recovered Friday, Saturday and Sunday. She says 140 of them have undergone examination by prosecutors and other specialists.

Ukrainian Deputy Prime Minister Iryna Vereshchuk says the mayor of the village of Motyzhyn in the Kyiv region was murdered while being held by Russian forces. Vereshchuk adds that there are 11 mayors and community heads in Russian captivity across Ukraine.

Russian Foreign Minister Sergey Lavrov dismissed the scenes outside Kyiv as a “stage-managed anti-Russian provocation.” Kremlin spokesperson Dmitry Peskov said the images contained “signs of video forgery and various fakes.”

The governor of Ukraine’s northern Sumy region says Russian forces no longer control any settlements in the area following their retreat, although some small groups of Russian troops remain.

The city of Sumy is near the border with Russia and was besieged by Russian troops when the invasion began in February, as other Russian forces pushed onward to join efforts to attack the Ukrainian capital, Kyiv, from the northeast. Russia began withdrawing troops from the area around Kyiv last week and says it is now focusing its efforts on the fighting in eastern Ukraine.

Sumy Gov. Dmytro Zhyvystskyy said on Ukrainian TV that “currently there are no occupied settlements” and that invading forces have pulled back across the border into Russia with their vehicles and artillery.

However, he added, “there are still individual units and small groups of Russian troops and now they are being caught” by the Ukrainian army and local Territorial Defense volunteers.

“A clean-up is happening across the whole territory of the region,” he said.

Russia probably plans to “deploy tens of thousands of soldiers” to eastern Ukraine as it shifts its focus to the country’s south and east, Biden’s national security adviser Jake Sullivan said on Monday.

“At this juncture we believe Russia is revising its war aims” to focus on “eastern and parts of southern Ukraine rather than target most of the territory,” Sullivan told reporters at the White House.

Sullivan said the Biden administration would announce fresh military assistance for Ukraine in the coming days and stressed that further sanctions against Russian energy are also on the table in talks with European allies.

On Sunday, Russian forces launched an airstrike on the Black Sea port of Odesa, in southern Ukraine, sending up clouds of dark smoke that veiled parts of the city. The Russian military said the targets were an oil processing plant and fuel depots around Odesa, which is Ukraine’s largest port and home to its navy.

The Odesa city council said Ukraine’s air defense shot down some missiles before they hit the city. Ukrainian military spokesman Vladyslav Nazarov said there were no casualties from the attack.

The smaller port of Mariupol, located to the east on the Sea of Azov, remained cut off from the rest of the country as Russian and Ukrainian soldiers fought for control of the besieged city. About 100,000 civilians, less than a quarter of the prewar population of 430,000, are believed to be trapped there with little or no food, water, fuel and medicine.

Ukrainian authorities said Russia agreed days ago to allow safe passage from Mariupol, which has been the site of some of the worst attacks and greatest suffering, but similar agreements have broken down repeatedly under continued shelling.

Mariupol is in the mostly Russian-speaking Donbas region, where Moscow-backed separatists have fought Ukrainian troops for eight years. Its capture would create an unbroken land corridor from Russia to Crimea, which Moscow seized from Ukraine in 2014.

President Zelenskyy called on all Ukrainians to do whatever they could “to foil the enemy’s tactics and weaken its capabilities.”

“Peace will not be the result of any decisions the enemy makes somewhere in Moscow. There is no need to entertain empty hopes that they will simply leave our land. We can only have peace by fighting,” Zelenskyy said Saturday.

While the geography of the battlefield morphed, little changed for many Ukrainians six weeks into a war that has sent more than 4 million people fleeing the country as refugees and displaced millions more from their homes.