Russian forces fired rockets at a nuclear research facility in the besieged city of Kharkiv, Ukrainian officials said.
A Ukrainian minister has warned that the bombing of the Kharkiv Institute of Physics and Technology could lead to a “major environmental disaster”.
The institute houses a facility called Neutron Source which contains a nuclear reactor used for research.
The same site was attacked by Russian troops earlier this month.
On Saturday, Ukraine’s parliament said it was not possible to assess the extent of the damage from the latest attack due to heavy fighting in the area.
Ukraine’s State Nuclear Regulatory Inspectorate reportedly said: “Continued bombardment may lead to serious radiological consequences with contamination of neighboring territories.”
The agency previously accused Russia of committing an “act of nuclear terrorism” by bombing the research center.
Emine Dzheppar, Ukrainian Deputy Foreign Minister, said: “The Russian aggressor fired ‘Grad’ rocket systems at the territory of the Kharkiv Institute, where the ‘Neutron Source’ nuclear facility is located. , in the active area of which 37 combustible nuclear cells were loaded.
“The destruction of a nuclear facility and nuclear material storage facilities could result in a major environmental catastrophe.
“Ukraine continues to gather evidence of (Russian) war crimes in The Hague.”
Kharkiv – Ukraine’s second largest city – has seen some of the worst shelling since the war began on February 24.
It comes after Russian forces took control of an area near the Chernobyl nuclear power plant, Interfax Ukraine news agency quoted the local mayor as saying.
Kyiv Region Governor Oleksandr Pavlyuk previously announced Slavutych’s capture in an online post.
The city sits just outside a safety exclusion zone around Chernobyl – the site of the world’s worst nuclear disaster in 1986 – where Ukrainian personnel continued to run the site even after it was occupied by the Russian forces.
The Russian army seized the disused Chernobyl power plant during the first week of the invasion as one of its first objectives.
“Slavutych has been under occupation since today. We have strongly defended our city… three deaths have been confirmed so far,” Mayor Yuri Fomichev said.
While Russia’s war in Ukraine is unlikely to see the use of nuclear weapons, there are fears that reckless Russian behavior could trigger another catastrophe.
The International Atomic Energy Agency said it was monitoring the situation closely and expressed concern about the ability of personnel to enter and exit the nuclear power plant.
HOT SPOT OF WAR
Pavlyuk said the Russians fired into the air to disperse a protest in the center of the city and threw stun grenades into the crowd.
Ukrainian presidential adviser Oleksiy Arestovych said the city had become a new hot spot in the war.
Russian troops have already stolen “unstable” nuclear samples after ransacking a laboratory at the Chernobyl power plant.
Putin’s men then allegedly destroyed the £5million lab filled with nuclear waste and located in the radioactive exclusion zone, according to Ukraine’s State Agency.
The agency said the stolen radionuclides are “very active”.
Radionuclides are unstable atoms of chemical elements that release radiation – the fact that they are now in Russian hands is a major concern.
He said he hoped Russian troops “will harm themselves and not the civilized world” with their deadly spoils from the Central Analytical Laboratory.
In a statement, the agency said, “The lab contained highly active samples and samples of radionuclides which are now in enemy hands.”
Worryingly, the levels of radiation emitted from the destruction of the lab cannot be measured because the Russians destroyed the monitoring system, according to state nuclear company Energoatom.
Communications with the site have been intermittent since the invasion.