Russian troops are firing at Ukraine's largest nuclear power plant, officials said.

"Russian army is firing from all sides upon Zaporizhzhia NPP, the largest nuclear power plant in Europe," Ukrainian Minister of Foreign Affairs Dmytro Kuleba tweeted early Friday. "Fire has already broke out. If it blows up, it will be 10 times larger than Chornobyl! Russians must IMMEDIATELY cease the fire, allow firefighters, establish a security zone!"

Andriy Tuz, a spokesperson for the power plant, warned in videos posted to Telegram that Russian shelling caused a fire at the plant. He said the first power unit was hit and that rescuers have not yet been able to put out the fire due to the ongoing shelling.

The International Atomic Energy Agency, the United Nations nuclear watchdog group, said only Unit 4 was in operation currently and "radiation levels and fire safety at the NPP is within the norm." The fire broke out at a training building outside the power plant, the IAEA said.

The power plant's livestream captured blasts and a fire at the facility.

The situation at Ukraine's largest nuclear power plant has become "critical," authorities had warned earlier Thursday as Russian troops approached the site.

"The battle is going on in the town of Enerhodar and on the road to the ZNPP (Zaporizhzhia Nuclear Power Plant) site," Ukraine's regulatory authority said in an "urgent letter" to the IAEA.

Ukraine reported that Russian tanks and infantry “broke through the block-post” to the town of Enerhodar, near the power plant, according to IAEA Director General Rafael Mariano Grossi, who called on troops to refrain from use of force.

During an emergency IAEA board of governors meeting this week, Grossi warned that an incident affecting nuclear facilities "could have severe consequences, aggravating human suffering and causing environmental harm" beyond Ukraine's borders.

IAEA tweeted it is aware of reports of shelling at the power plant and is in contact with Ukrainian authorities.

-ABC News' Cindy Smith, Kirit Radia and Bill Hutchinson

Facebook restrictions in Russia are becoming more extensive, according to internet monitoring agency NetBlocks.

The restrictions impact internet providers including Rostelecom and Beeline, according to NetBlocks.

They follow restrictions placed on Twitter and Facebook in recent days that have caused some content to take an extremely long take to load, if at all, on major providers, making the platforms "largely unusable," NetBlocks reported.

Circumvention is possible using VPN services.

The independent Russian news site Meduza also reported Thursday that it is inaccessible for some readers in Russia.

-ABC News' Christine Theodorou and Patrick Reevell

Volkswagen is the latest automaker to pause its business in Russia following the invasion of Ukraine.

The German car company announced Thursday that its board has decided to stop the production of cars in Russia "until further notice."

It also decided to immediately stop vehicle exports to Russia, Volkswagen said.

"We are convinced that a sustainable solution to the conflict can only be found on the basis of international law," the company said in a statement. "With the extensive interruption of business activities in Russia, the Executive Board is reviewing the consequences from the overall situation, during this period of great uncertainty and upheaval,"

Volkswagen has production sites in Kaluga and Nizhny Novgorod.

Earlier this week, General Motors and Volvo Cars said they will suspend vehicle exports to Russia until further notice. Mercedes Benz said Wednesday it will pause exports and manufacturing in Russia until further notice. Ford has also suspended its operations in the country.

-ABC News' Christine Theodorou

The U.S. Department of Homeland Security has granted Ukrainians with temporary protected status (TPS) amid the conflict with Russia, officials said.

"Russia’s premeditated and unprovoked attack on Ukraine has resulted in an ongoing war, senseless violence, and Ukrainians forced to seek refuge in other countries,” Homeland Security Secretary Alejandro Mayorkas said in a statement. "In these extraordinary times, we will continue to offer our support and protection to Ukrainian nationals in the United States."

Individuals must have continuously resided in the U.S. as of March 1 to be eligible; Ukrainians who arrive after that date will not be eligible. The designation, which will last at least 18 months, allows migrants not otherwise in the U.S. on a legal basis to continue to live and work in the country and not be subject to deportation during that time.

Immigration and Customs Enforcement paused deportations to Ukraine as of Thursday, an agency spokesperson confirmed to ABC News.

A country may be designated for TPS due to ongoing armed conflict, environmental disasters or "extraordinary and temporary conditions." The U.S. Department of Homeland Security noted the conditions Ukrainians might face if they are repatriated home.

"This invasion has caused a humanitarian crisis with significant numbers of individuals fleeing and damage to civilian infrastructure that has left many without electricity or water or access to food, basic supplies, shelter and emergency medical services," the department said.

The announcement follows pressure from both sides of the aisle to extend TPS to Ukrainians in the U.S. as the war continues.

Senate Majority Leader Chuck Schumer applauded the Biden administration for "taking decisive action so that Ukrainians can stay safely in America,"

"The United States stands with the people of Ukraine," he said in a statement.

-ABC News' Aaron Katersky, Conor Finnegan and Luke Barr