The Kremlin has stepped up its claims that Kyiv is planning a provocation involving the use of a “dirty bomb,” sparking fears among Western governments that Moscow is seeking a pretext for further escalation.

Russian state media outlet RIA Novosti reported on Wednesday that Kyiv is plotting a type of false flag attack with radioactive materials, citing a “source familiar with the situation.” Ukrainian aerospace manufacturer PA Pivdenmash has “already made a dummy missile of the [Russian] Iskander complex, the head cluster of which is planned to be filled with radioactive material, and then “shot down” by Ukrainian air defenses over the Chernobyl Exclusion Zone in order to announce Russia’s launch of a nuclear charge,” RIA’s source said. Kyiv will purportedly show fragments of the dummy missile to Western and Ukrainian media sources in order to “convince the Western public of Russia’s guilt,” the source added. RIA did not provide any evidence to corroborate the alleged Ukrainian scheme.

Russian officials have insisted over the past week—without providing proof of their assertions—that Ukraine intends to orchestrate a provocation involving a dirty bomb, commonly defined as a conventional weapon combined with radioactive material. Russia formally registered its dirty bomb claim on Tuesday in a letter to the United Nations (UN) Security Council and UN António Guterres. “We will regard the use of the ‘dirty bomb’ by the Kiev regime as an act of nuclear terrorism,” wrote Russia’s UN ambassador Vassily Nebenzia, according to Reuters. “We urge the Western countries to exert their influence on the regime in Kiev to abandon its dangerous plans threatening international peace and security.”

Kremlin spokesman Dmitry Peskov said on Wednesday Russia has “proof that Ukraine is preparing for such a terrorist act of sabotage,” urging the international community to “take active steps in terms of preventing such irresponsible behavior by the Kiev regime.” Russian Foreign Ministry official Konstantin Vorontsov accused Western governments, without elaborating on which state actors are involved, of helping Kyiv to develop a dirty bomb. “The goal is obvious: to accuse Russia of using weapons of mass destruction,” he said according to the Russian state news outlet TASS.

Ukraine has rebuffed Russia’s allegations. “This is a lie,” Ukrainian foreign minister Dmytro Kuleba said. “Ukraine is a dedicated and responsible member of the treaty on the non-proliferation of nuclear weapons. We have never had, do not have, and do not plan to develop any dirty bombs,” he added, noting that Kyiv has invited International Atomic Energy Agency (IAEA) experts to inspect the facilities that Russia “falsely claims” are being used to develop a dirty bomb.

Western officials have raised concerns that the Kremlin will leverage its dirty bomb claims to justify acts of escalation in Ukraine, though the White Has says there are currently no indications that Russia is preparing to use nuclear weapons. “We continue to see nothing in the way of preparations by the Russian side for the use of nuclear weapons and nothing with respect to the potential use for a dirty bomb at this point,” John Kirby, the National Security Council Coordinator for Strategic Communications, told reporters. “We’re watching this as closely as we can.”

Mark Episkopos is a national security reporter for the National Interest.

Image: Reuters.