Russia-Ukraine updates: US sanctions Russian military shipbuilder, diamond miner

At least 847 civilians, including 64 children, have been killed in Ukraine since Russia invaded on Feb. 24, according to the United Nations.

Another 1,399 have been injured, it said.

The casualties, recorded by the Office of the United Nations High Commissioner for Human Rights, are believed to be "considerably higher" since officials have not been able to verify information in areas where there is intense fighting, the office said.

"Most of the civilian casualties recorded were caused by the use of explosive weapons with a wide impact area, including shelling from heavy artillery and multiple-launch rocket systems, and missile and air strikes," it said.

-ABC News' Jason Volack

The Kremlin confirmed Saturday that it used hypersonic missiles for the first time since invading Ukraine.

Russia used the Kinzhal aviation missile system, with hypersonic aeroballistic missiles, on the village of Delyatyn in Ukraine on Friday, according to Igor Konashenkov, a spokesman for the Russian Defense Ministry.

"On March 18, the Kinzhal aerial missile system equipped with hypersonic aero-ballistic missiles destroyed a large underground missile and air ammunition depot of the Ukrainian Armed Forces in the settlement of Deliatyn in the Ivano-Frankivsk region," Konashenkov said at a briefing on Saturday.

The Russian military claims it is capable of hitting targets at a range of more than 2,000 kilometers.

At least 562 prisoners of war are being held in Ukraine, Irina Vereshchuk, the head of the country's Ministry of Reintegration, a ministry established in 2016 to manage occupied Ukrainian territories, said in an interview with Ukrainian news service TSN on Saturday.

Vereshchuk said they are being treated according to international humanitarian law.

At least 30 people were killed in a strike on a Ukrainian military barrack south of Mykolaiv on Friday, according to a witness.

A civilian working with the Ukrainian military told ABC News that more than 30 people were killed in the attack– believed to be in retaliation to damage done to the Russian controlled facility in Kherson.

On Friday, Mykolaiv's mayor said that "dozens" of troops were killed in the strike.

Mykolaiv's governor said the rescue operation is ongoing and no official figures on casualties will be released until it's over.

-ABC News' Dada Jovanovic