The U.S. embassy in Kyiv, which has evacuated to Poland, is calling Russia's attack on a nuclear power plant a war crime, Saying on Twitter "Putin's shelling of Europe's largest nuclear plant takes his reign of terror one step further."
A lawyer with experience at the International Criminal Court told Newsy that court would agree.
"The International Criminal Court will consider an attack on a nuclear power plant to be a war crime," said Göran Sluiter, criminal law professor at the University Of Amsterdam. "Such an attack will have devastating consequences for civilians in the area and also for the environment."
Russian troops now control two of Ukraine's nuclear power plants.
"What you saw last night was reckless action of war in and around a nuclear power plant," said NATO Secretary General Jens Stoltenberg.
On Thursday night, Russian forces broke through a blockade of Ukrainians defending the country's largest nuclear power plant and began firing, according to the company that operates the Zaporizhzhia nuclear power plant. A projectile hit a training building, causing a fire to break out. It was later extinguished, but now Russian forces occupy the plant.
"This just underscores how reckless the Russian invasion has been and how indiscriminate their targeting seems to be," said Pentagon press secretary John Kirby. "I mean it just raises the level of potential catastrophe to a level that, again, nobody wants to see."
Nuclear experts tell Newsy if Russian troops continue down their reckless path, the dangers could be felt beyond war-torn Ukraine.
"If one of these reactors melts down, we're looking at a catastrophe of unimaginable proportions, even potentially affecting the United States," said Linda Pentz Gunter, founder of Beyond Nuclear. "It's a major concern and very alarming."
The head of the International Atomic Energy Agency says no radioactive material has been released, but that he "cannot rely on this good fortune to continue."
And analysts are concerned about how Ukrainian station workers will be able to handle the pressure and whether they'll continue operating the reactors.
"We don't really know who's in charge there," Pentz Gunter said. "We don't know if the military personnel are skilled in reactor management. They may be 18 year old soldiers."
Russian troops last week overtook the former Chernobyl nuclear power plant, the site of a major accident in 1986.
Ukraine has three other active nuclear power plants and defense analysts with a firm called Rochan say Russian forces are nearing another one, the South Ukraine Nuclear Power Plant, with forces about 15 miles north.
"I don't believe that Russia had a preplanned strategy to attack the Ukrainian nuclear power plants or Chernobyl," said Gen. Chuck Wald, former deputy commander of U.S. European Command. "I think that came up as Russia has become bogged down in their attacks on Ukraine."
Russia's Defense Ministry Spokesman falsely blamed the fire at Zaporizhzhia nuclear power plant on a "Ukrainian subversion group."
"I think Russia's making up their strategy now as they go along," Wald said. "I don't think that was in the playbook initially, and I think they're there, frankly, I think they're scrambling, and I think it's they're going to look back on this and go, What in the world are we doing here now? And I just don't think they have a real coherent plan."
Ukrainian and U.S. authorities say the plant was designed to withstand shelling, but analysts say these facilities weren't built to withstand sustained war.