The deputy mayor of embattled Mariupol claimed Thursday that some of the city's residents are being "forcibly detained in appalling conditions" in Russian "filtration camps" in a nearby village.

"Filtration camps in the village of Bezymyanne have been turned into a real ghetto for Mariupol residents," Mariupol Deputy Mayor Petro Andryushchenko said in a statement via Telegram. "This is the most horrible story that needs to be told to the whole world. Without exaggeration, this is a new page in Russia's war crime that is happening right now."

Andryushchenko alleged that, about a month ago, Russian forces took thousands of men from several Mariupol neighborhoods, confiscated their passports and placed them in filtration camps in Bezymianny, about 20 miles from Mariupol. As for the women who were left behind, they don't leave their homes because they fear being raped by Russian troops who have settled in the area, according to the deputy mayor.

"All this once again shows the realities of the occupation," he said.

Andryushchenko posted videos on Telegram alongside his statement, purportedly showing a school in Bezymianny that he alleged Russian force are using as a filtration camp. He claimed that the detainees are forced to sleep on the floor, don't have access to medical care and can only wash themselves in a single sink with cold water. He alleged that all detainees, including the sick and those with disabilities, are forced to do landscaping work in the village. He also claimed that at least one man has died because he was refused medical assistance and another has been diagnosed with tuberculosis.

The deputy mayor alleged that the Russian military is planning to dress the detainees in the uniform of the Ukrainian military and parade them as "prisoners" during a celebration in Mariupol on Monday to coincide with Moscow's Victory Day Parade, which celebrates Russia's victory over Nazi Germany in World War II.

The Russian military claimed Wednesday to have taken complete control of Mariupol, a strategic port city in eastern Ukraine's war-torn Donetsk Oblast that has been under heavy Russian bombardment since the start of the invasion on Feb. 24. Ukrainian fighters and civilians who remain in Mariupol are holed up inside the sprawling Azovstal Iron and Steel Works plant, which has a network of underground tunnels and bunkers.

ABC News recently spoke to Denys Prokopenko, a commander of the Azov Regiment, a far-right group now part of the Ukrainian military that was among the units defending Mariupol. Prokopenko is now trapped inside the Azovstal plant with others said the fighters there have tried to initiate a cease-fire with Russian force to create conditions that would allow people to flee. But he said there are grave concerns about where those who choose to leave will end up because Russian authorities have said that all civilians will be allowed to choose to go to either Ukrainian- or Russian-controlled territory, but only after processing through Russian filtration camps.

"If our people are captured against their will and forcefully, forcibly relocated to the Russians, it's unacceptable," Prokopenko told ABC News.

-ABC News' Clark Bentson, Dragana Jovanovic, Ian Pannell and Max Uzol

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.

White House national security advisor Jake Sullivan hinted Thursday of more sanctions coming against Russia in the "next week or two" aimed at targeting ways Moscow is evading sanctions already imposed.

“Where our focus will be over the course of the coming days is on evasion,” Sullivan said Thursday at the Economic Club of Washington. “As Russia tries to adjust to the fact that it’s under this massive economic pressure, what steps do they take to try to evade our sanctions and how do we crack down on that? And I think we'll have some announcements in the next week or two that identify targets that are trying to facilitate that evasion both inside Russia and beyond."

When Sullivan was asked whether sanctions will automatically be lifted if a negotiated peace deal between Russia and Ukraine is worked out, he appeared cautious with his words, saying, “a lot of that depends on what the shape and scope” of the agreement is.

“A lot of it depends on what the Ukrainians, in consultation with us and the Europeans come to agree to," Sullivan said. "You know, we're not going to do a deal over the head of the Ukrainians where we give a bunch of sanctions relief to Russia. But if some measure of sanctions relief were built in to some credible diplomatic solution led by the Ukrainians, that's something that we would happily discuss."

But Sullivan said Russian oligarchs shouldn't expect to ever get back their yachts and other assets seized under sanctions that have been imposed, saying the ultimate goal is "not to give them back” once the war is over.

“The president is actively looking at how we can deal with the fact that as we seize these assets, our goal is not to give them back. Our goal is to put them to a better use than that," Sullivan said. "But I'll be careful in what I say today because there's an ongoing kind of policy process around how we end up dealing with that question. But, rest assured, that the goal is not just to sit on them for a while."

-ABC News' Justin Gomez