Following graphic images of casualties coming out of Bucha, Ukraine, after Russian military withdrawal, Ukrainian President President Volodymyr Zelenskyy has strong words about what he called, "concentrated evil," in his daily address Sunday. Here are excerpts from that address:

"Hundreds of people were killed. Tortured, executed civilians. Corpses on the streets. Mined area. Even the bodies of the dead were mined!"

"Concentrated evil has come to our land. Murderers. Torturers. Rapists. Looters. Who call themselves the army. And who deserve only death after what they did."

"I want every mother of every Russian soldier to see the bodies of the killed people in Bucha, in Irpin, in Hostomel. What did they do? Why were they killed? What did the man who was riding his bicycle down the street do? Why were ordinary civilians in an ordinary peaceful city tortured to death? Why were women strangled after their earrings were ripped out of their ears? How could women be raped and killed in front of children? How could their corpses be desecrated even after death? Why did they crush the bodies of people with tanks? What did the Ukrainian city of Bucha do to your Russia? How did all this become possible?"

"All partners of Ukraine will be informed in detail about what happened in the temporarily occupied territory of our state. War crimes in Bucha and other cities during the Russian occupation will also be considered by the UN Security Council on Tuesday."

Zelenslyy also invited former German Chancellor Angela Merkel and former French President Nicolas Sarkozy to Ukraine to witness the carnage.

"We do not blame the West. We do not blame anyone but the specific Russian military who did this against our people," Zelenskyy, who has pleaded with the U.S. and NATO allies to create a no-fly zone over Ukraine, a measure so far, that President Joe Biden and other Western leaders have refused to do, said.

-ABC News' Christine Theodorou

Several world leaders on Sunday reacted to images shared by Ukraine's president's office, claiming to show the bodies of civilians scattered on the streets after the withdrawal of Russian troops from areas northwest of Kyiv.

In some of the photos, unarmed civilians appear to have been executed with their hands tied behind their backs.

NATO Secretary-General Jens Stoltenberg called the deaths of civilians in Bucha a “brutality" on CNN's "State of the Union" show, and said “I strongly welcome” an investigation by International Criminal Court, which has opened an investigation into war crimes in Ukraine.

"You can't but [see] those images as a punch to the gut ... Since the aggression, we've come out and said that we believe Russian forces have committed war crimes and we've been working to document that, to provide the information that we have to the relevant institutions and organizations that will put all of this together," U.S. Secretary of State Anthony Blinken told CNN's State of the Union Sunday.

"Russia’s despicable attacks against innocent civilians in Irpin and Bucha are yet more evidence that Putin and his army are committing war crimes in Ukraine," U.K. Prime Minister Boris Johnson said. "No denial or disinformation from the Kremlin can hide what we all know to be the truth -- Putin is desperate, his invasion is failing, and Ukraine’s resolve has never been stronger. I will do everything in my power to starve Putin’s war machine. We are stepping up our sanctions and military support, as well as bolstering our humanitarian support package to help those in need on the ground. The UK has been at the forefront of supporting the international Criminal Court's investigation into atrocities committed in Ukraine. The Justice Secretary has authorized additional financial support and the deployment of specialist investigators – we will not rest until justice is served," Johnson said.

Other world leaders expressed their feelings on social media.

"Appalled by reports of unspeakable horrors in areas from which Russia is withdrawing. An independent investigation is urgently needed. Perpetrators of war crimes will be held accountable," European Commission President Ursula von der Leyen posted on Twitter.

"Mass killings of Ukrainian civilians by #Russia are clear war crimes," Estonia's Prime Minister Kaja Kallas said on Twitter.. "We need courage, moral clarity and more action to stop it. Indifference is the mother of all crimes. Evidence must be gathered, saved for trials, and perpetrators must face justice. We need a 5th round of strong EU sanctions as soon as possible. Finally, our top priority should be increased military aid to #Ukraine. They need it to take back their cities and free people from Russian occupation and repression. #StandWithUkraine"

The prime minister of Slovenia, Janez Janša also weighed in on Twitter: "This are massive crimes against humanity. Russian army behaves as a horde of KGB executioners at Katyn. And at many other places after and before. Never bearing responsibility. After seeing #BuchaMassacre, we are terrified to even imagine what we will see in #Mariupol."

Belgium's Foreign Minister Sophie Wilmès, also posted om Twitter: "The images from the city of #Bucha confirm the fears we have had since February, which have led us to support several international investigations, including that of the @IntlCrimCourt. Impunity must not be allowed."

"Terrible images of destruction and reported executions of civilians in Bucha, Ukraine, in wake of Russian aggression. Reminiscent of darkest scenes from European history. To fight impunity :flag-se: will support @IntlCrimCourt investigation, incl financially and with seconded personnel," Sweden's prime minister, Magdalena Andersson, also posted to Twitter

-ABC News' Christine Theodorou

The Minister for Foreign Affairs of Ukraine, Dmytro Kuleba, called on the International Criminal Court and other international organizations to investigate Russians committing war crimes and crimes against humanity.

"I urge the International Criminal Court and international organizations to send their missions to Bucha and other liberated towns and villages of the Kyiv region, in cooperation with Ukrainian law enforcement agencies, to collect all evidence of Russian war crimes as carefully as possible," Kuleba said Sunday on Times UK radio.

"We are still collecting and looking for bodies, but the toll has already gone into the hundreds. Dead bodies lie on the streets. They killed civilians while in and out of these villages and towns," he said.

-ABC News' Yulia Drozd

Plumes of dark smoke rose on Sunday over Odessa, Ukraine, after an early morning Russian attack on the strategic and historic port city.

Missiles struck critical infrastructure facilities in the southern city, which sits on the Black Sea, Ukraine’s southern command announced. Casualties have not yet been reported.

According to the Ukrainian military, some Russian missiles were shot down by air defenses.

Missiles first hit Odessa on the opening night of Russia's invasion and again late last month. Residents have been bracing for Russia to launch an offensive to take the city.

Russia’s military on Sunday claimed the attack destroyed an oil refinery and three fuel depots, which had been supplying fuel to a nearby group of Ukrainian troops.

-ABC News’ Yulia Drozd

All Russian troops have left the Ukrainian cities of Kyiv and Chernihiv, withdrawing north toward the borders of Belarus and Russia to consolidate before likely redeploying to the Donbas region in eastern Ukraine, a senior U.S. defense official told reporters Wednesday.

But even with the Russians gone, the territory remains treacherous.

"There are some indications that they left behind mines and things like that, so the Ukrainians are being somewhat careful in some areas north of Kyiv as they begin to clear the ground and clear the territory and re-occupy it," the official said.

While the U.S. hasn't yet seen these troops redeploy elsewhere in Ukraine, it'll likely happen soon, according to the official. Ukrainian forces are preparing for a major fight in Donbas, the official said.

The official also said the Pentagon is "monitoring" an apparent nitric acid explosion in Ukraine's Luhansk region, which Russia blamed on Ukraine.

"We've seen the Russians claim that this was a Ukrainian attack on this. We do not believe that is true," the official said. "We do believe that the Russians are responsible, but exactly what they used when they did it, why they did it, what the damage is, we just don't have that level of detail," the official said.

The official also noted that a small number of Ukrainians currently in the U.S. for "professional military education" were pulled aside for a couple days of training on Switchblade drones, which the U.S. is sending overseas as part of its military aid, according to the official.

"Although it's not a very difficult system to operate, we took advantage of having them in the country to give them some rudimentary training on that," the official said.

-ABC News' Matt Seyler