The Russian Defense Ministry claimed it prevented an attempt by the Ukrainians to hit Kakhovskaya hydroelectric power station with two Tochka-U tactical missiles on Friday morning.

Russia claimed the missiles were shot down in mid-air and shrapnel from one of them fell on Novaya Kakhovka, Kherson region, damaging Kindergarten and residential buildings.

The facility regulates the flow of the Dnepr River, supplies electricity to Kherson region, and supplies water to agricultural areas in southern Ukraine and northern Crimea, according to Russia.

Russia claimed if the station was hit, it would have caused the release of Dnepr water and caused flooding of Kherson region settlements.

More than 900 bodies of civilians were discovered in the Kyiv region following the withdrawal of Russian forces, Kyiv region Police Chief Andriy Nebytov said in a press briefing.

"I want to say that the number of killed civilians has surpassed 900 - and I emphasize, these are civilians, whose bodies we have discovered and handed over for forensic examination," Nebytov said.

He later said, "Bucha has the most significant number of victims. This suggests that the occupiers, the units, that operated in Bucha, were the most brutal. The most victims were found in Bucha, where there are more than 350 corpses."

Nebytov claimed Russian forces were forcing Ukrainians to work for Russia.

"We understand that during the occupation, the Russian army established a certain modus operandi, trying to find people who have influence over the community and force them to work for Russia," Nebytov said.

Nebytov said the bodies had been abandoned in the streets or were buried in temporary graves.

"There were two mass graves, if we can say so. There was a person, a communal worker, who worked before the war in Bucha. He stayed in the city and actually asked the occupiers to allow him to take away the people's bodies from the streets. He buried them in two graves. The first was for 40 dead people, the second for 57 dead people," Nebytov said.

He added: "Among them was one of our policemen, a criminal investigation officer, who unfortunately was also shot with a small weapon. Most of these bodies have been examined, and I want to say that 95% of the people were killed by sniper rifles or small arms. That is, we understand that during the occupation, people were shot in the streets."

-ABC News' Alexandra Faul

Senior U.S. defense officials believe Russia's sunken Moskva cruiser was hit by two Ukrainian-launched Neptune missiles, bolstering claims from Ukrainian officials on Thursday.

The officials could not confirm how many Russian crew members were injured or killed in the attack or subsequent fire and eventual sinking.

-ABC News' Matt Seyler

The U.S. received a formal diplomatic note from Russia protesting U.S. and NATO military aid to Ukraine and accused them of violating principles and potentially risking weapons falling into bad actors' hands, a U.S. official briefed on the note confirmed to ABC News.

The Russian government previously warned the U.S. and NATO against providing weapons and other military equipment. Both Russian Foreign Minister Sergei Lavrov and one of his deputies, Sergei Ryabkov, also warned that Western convoys providing military aid were "legitimate targets" for Russian attack.

The White House referred questions to the State Department, but a State Department spokesperson declined to comment on "any private diplomatic correspondence."

State Department spokesperson Ned Price also declined to confirm the report, but during an interview with CNN, said, "The Russians have said some things privately. They have said some things publicly. Nothing will dissuade us from the strategy that we've embarked on."

Another source said it shows the effectiveness of U.S. weapon deliveries and security assistance, that Russia is upset is happening.

Price also told CNN that the war in Ukraine could drag on through the end of this year into next year, something other U.S. officials, including Chairman of the Joint Chiefs of Staff Mark Milley, have warned about as well.

"It is possible ... but what we're trying to do is to shorten this conflict," Price told CNN, by providing Ukraine with "unprecedented amount of security assistance" and applying pressure on Russia.

The Washington Post first reported on the diplomatic note.

-ABC News' Conor Finnegan, Matt Seyler, Justin Gomez and Shannon Crawford

Jalina Porter, the State Department's deputy spokesperson, is responding to the Russian attack at a Ukraine train station that killed at least 50, saying, "We can no longer be surprised by the Kremlin's repugnant disregard for human life."

Five children were among those killed when Russian rockets struck the station in Kramatorsk in Donetsk Oblast on Friday morning, according to Ukraine's state-owned railway company. At least 100 people were injured, according to Donetsk Oblast Gov. Pavlo Kyrylenko.

Russia has denied involvement in the attack, which occurred as "thousands" of civilians fleeing the Russian invasion were at the train station waiting to be taken to "safer regions of Ukraine," according to Kyrylenko.

"Civilians are killed when they stay in their homes, and they're killed when they try to leave," Porter said. "Actions like these demonstrate why Russia did not belong on the U.N. Human Rights Council, and they also reinforce the U.S. assessment that members of Russian forces are committing war crimes in Ukraine."

Porter declined to say if the department considers the train station attack a war crime, saying, "Assessing individual criminal liability in specific cases is the responsibility of courts, as well as other investigatory bodies. But as the secretary, Secretary [of State Antony] Blinken, has said, 'Those responsible for war crimes and other atrocities committed in Ukraine will be held to account.'"

-ABC News' Conor Finnegan