Russia claimed Sunday that Ukrainian intelligence was preparing to carry out a false flag operation involving a nuclear reactor in eastern Ukraine near the Russian border.

The Russian Defense Ministry said in a statement that the Security Service of Ukraine (SBU) along with Ukrainian nationalists from the Azov battalion planned to blow up the reactor at an experimental nuclear facility at the Institute of Physics and Technology in Kharkiv, where clashes were taking place between Russian and Ukrainian forces.

"The Russian Armed Forces will be accused of launching a missile attack on the experimental nuclear facility," the statement said, creating an ecological catastrophe.

Russia's war on Ukraine has been met with outrage from the international community, with the European Union, UK and US among others imposing a range of economic sanctions on Moscow.

At least 364 civilians have been killed and 759 others injured in Ukraine since Russia launched a war in the Eastern European country on Feb. 24, according to UN figures, with the real toll feared to be higher.

More than 1.5 million people have fled Ukraine to neighboring countries, according to the UN Refugee Agency.