Russia-Ukraine updates: 2 US veterans who joined Ukrainian forces missing

Four staff members of World Central Kitchen were injured in a shelling in Kharkiv in northeast Ukraine on Saturday, the organization said.

"Food heroes them all!" chef and founder Jose Andres said on Twitter. "Relief that so far that just were 4 wounded…..praying for them!"

The "Russian attacks must stop against civilian buildings and markets and churches and schools," he added.

The organization, which responds to disaster situations, has been providing meals to refugee families leaving Ukraine.

World Central Kitchen CEO Nate Mook said a missile struck one of the World Central Kitchen's partner restaurants in Kharkiv, which has seen heavy shelling.

"As you can see, tremendous amounts of damage," Mook said in a video posted to Twitter Saturday from the scene, standing before debris and burned-out cars.

Mook said "a number" of staff were wounded and hospitalized, and that one person not affiliated with the organization was killed.

"Just a tremendous amount of carnage left behind for no reason," he said. "Just absolutely horrific brutality."

Russian forces have not completely captured Mariupol, but the army is constantly calling on additional units to storm the city, Ukrainian defense ministry spokesperson Oleksandr Motuzyanyk said in a press conference.

"The situation in Mariupol is difficult and hard. Fighting is happening right now. The Russian army is constantly calling on additional units to storm the city," Motuzyanyk said.

Russian forces intend to totally close the city for entry and exit and prohibit movement between the districts and they are filtering out the men left in the city, advisor to the mayor Petro Andriushchenko alleged in a post on Telegram.

"After standard filtration bullying (interrogation, checking gadgets, examining the body) the men are separated from others and are subjected to separate interrogations, including an imitation of an execution," Andriushchenko claimed.

He added: "In general, we can say that from 5 up to 10% do not pass the filtration and after that are exported to Dokuchaevsk and Donetsk. Their further fate is not known."

Russian warships, armed with "Caliber" naval cruise missiles, in the Black Sea pose a threat against Ukrainian defense industry and logistics infrastructure, spokesman of the general staff of Ukraine Armed Forces, Alexandra Stupun said.

Stupun added: "In the waters of the Sea of Azov, the enemy's naval group continues to carry out tasks to block the port of Mariupol and provide fire support in the coastal direction."

-ABC News' Somayeh Malekian

The Romanian Naval Administration announced it has banned Russian-flagged ships from entering its ports.

The ban will take effect on Sunday.

-ABC News' Somayeh Malekian

Russia announced it has banned British Prime Minister Boris Johnson and several members of his cabinet from entering its territory in response to what it claims are the British government's hostilities, the Russian Foreign Ministry said on Saturday.

Russia said the ban was in response to sanctions placed on Russian senior officials by the British government.

In addition to Johnson, Russia banned the U.K.'s secretary of state for foreign, commonwealth and development affairs; its secretary of state for defense; the deputy prime minister and secretary of state for justice; and several other members of the British government.