Russia said on Sunday that Ukraine was planning to stage a nuclear incident on its territory to pin the blame on Moscow ahead of a United Nations meeting, without providing evidence for the accusation.

Since the start of its invasion of Ukraine nearly a year ago, Russia has repeatedly accused Kyiv of planning “false flag” operations with non-conventional weapons, using biological or radioactive materials. No such attack has materialized.

Russia’s defense ministry said in a statement that radioactive substances had been transported to Ukraine from a European country and Kyiv was preparing a large-scale “provocation”.

“The aim of the provocation is to accuse Russia’s army of allegedly carrying out indiscriminate strikes on hazardous radioactive facilities in Ukraine, leading to the leakage of radioactive substances and contamination of the area,” it said.

Ukraine and its allies have dismissed such accusations as cynical attempts to spread disinformation and has accused Moscow of planning incidents itself in a bid to blame Ukraine.