At least 25 civilians were injured by Russian shelling on residential areas and the central part of Kramatorsk on Wednesday night, according to the local city council.

Six of the wounded required hospitalization, and at least nine homes, a school as well as various civilian infrastructure sustained damaged, the Kramatorsk City Council said in a statement via Telegram.

Kramatorsk Mayor Oleksandr Honcharenko confirmed in a statement via Facebook that a kindergarten was seriously damaged.

Kramatorsk is a city in eastern Ukraine's war-torn Donetsk Oblast.

-ABC News' Max Uzol

More than 300 civilians have been evacuated from the besieged Ukrainian port city of Mariupol and surrounding areas, officials said late Wednesday.

The International Committee of the Red Cross said it facilitated the safe passage of the civilians in coordination with the United Nations and both sides of the Russia-Ukraine conflict. The evacuees arrived Wednesday in Zaporizhzhia, a Ukrainian government-controlled city about 140 miles northwest of Mariupol.

"We are relieved that more lives have been spared," Pascal Hundt, the ICRC's head of delegation in Ukraine, said in a statement Wednesday night. "We welcome the renewed efforts of the parties with regards to safe passage operations. They remain crucial and urgent in light of the immense suffering of the civilians."

Ukrainian Deputy Prime Minister Iryna Vereshchuk confirmed that 344 people were evacuated to Zaporizhzhia from the Mariupol area, Manhush, Berdyansk, Tokmak and Vasylivka.

The evacuation did not include civilians trapped inside the Azovstal Iron and Steel Works plant, the last pocket of Ukrainian resistance in Mariupol.

-ABC News' Natalya Kushnir and Cindy Smith

Ukrainian military officer Denys Procopenko said Russians have breached the Azovstal Iron and Steel Works plant in Mariupol, where hundreds of civilians remain.

He said heavy fighting is ongoing.

Procopenko is commander of the Azov regiment, which is a far-right paramilitary that's now incorporated into Ukrainian government security forces.

The Russian Defense Ministry said a humanitarian corridor will open this week for the evacuation of civilians from the Azovstal Iron and Steel Works plant in Mariupol.

The humanitarian corridor will be open Thursday, Friday and Saturday from 8 a.m. to 6 p.m. Moscow time.

Russia said its forces will "cease any hostilities" during that time.

Ukrainian President Volodymyr Zelenskyy spoke with United Nations Secretary-General António Guterres on Wednesday, asking for the U.N.'s help in evacuating "all the wounded" from the plant.

"The lives of the people who remain there are in danger. Everyone is important to us," Zelenskyy said, according to a statement from his office.

Hundreds of civilians are believed to be trapped in the plant.

The plant, which stretches over 4.2 square miles, has been facing bombardment and shelling. It's the last pocket of Ukrainian resistance in Mariupol; Russia claimed Wednesday that its military had taken complete control of the city.

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