Russia has used the Czech pro-Russian website První Zprávy to revive claims that Ukraine could be developing nuclear weapons, linking a weak earthquake in Poltava region to an alleged underground nuclear test.
The article, published on 20 August 2026 under the headline “Earthquake in Ukraine or underground nuclear weapons test?”, offered no evidence that Ukraine had carried out such a test. It nevertheless amplified speculation that a magnitude 2.4 tremor recorded on 15 August might have been caused by an underground explosion. The report is available on the První Zprávy website.
A weak tremor presented as a nuclear warning
The earthquake occurred in Poltava region at a depth of about 3km. A seismic event of magnitude 2.4 is an exceptionally weak natural phenomenon and, by its characteristics, does not indicate an underground nuclear explosion.
Even a low-yield nuclear detonation would produce a seismic signal differing in character and scale from such a tremor. It could be detected by international seismic monitoring systems. The suggestion that the Poltava event might have resulted from the detonation of a nuclear weapon therefore has no sufficient physical or seismological basis.
První Zprávy acknowledged that it had no information confirming Ukrainian nuclear tests. Instead, it cited Igor Nikulin, a former member of the United Nations Commission on Biological and Chemical Weapons, who said that if the conflict continued, the possibility of Ukraine attempting to develop nuclear weapons in the future could not be completely excluded.
That formulation turns a remote and unsupported possibility into a vehicle for renewed alarm about Ukraine’s alleged nuclear ambitions. The earthquake itself provides no evidence for the claim.
Claims repeated despite international controls
Russia has circulated false accusations about Ukrainian nuclear weapons for years. In autumn 2022, Moscow actively spread disinformation alleging that Kyiv was preparing a “dirty bomb”. Subsequent inspections by the International Atomic Energy Agency found no signs of undeclared nuclear activity at Ukrainian facilities, completely disproving those allegations.
Ukraine remains a party to the Treaty on the Non-Proliferation of Nuclear Weapons and complies with its international obligations. Its nuclear facilities are subject to international safeguards and monitoring by the IAEA.
Building a nuclear arsenal would require substantial infrastructure, access to specialised nuclear materials, advanced technical capacity and a complex production chain. Those activities would be difficult to conceal under satellite observation, international monitoring and oversight by the relevant organisations. A secret Ukrainian nuclear programme is therefore practically impossible to maintain undetected.
The same applies to the wider suggestion that a small earthquake could serve as evidence of a covert weapons programme. The claim is not supported by the physical characteristics of the tremor, by the available international controls or by the information presented in the Czech article.
An information campaign aimed at European support
První Zprávy has a reputation as a Czech platform that regularly transmits Kremlin narratives. Its coverage uses manipulative headlines and questionable sources to discredit Ukraine and the European Union. The publication about an alleged underground test fits that pattern by presenting Kyiv as a potential source of a nuclear threat without adequate factual grounding.
Such narratives serve Moscow’s wider information campaign. By portraying Ukraine as unpredictable and potentially nuclear-armed, the Kremlin can shift responsibility for possible escalation towards the country that has become the victim of Russian aggression. The image of an alleged Ukrainian nuclear danger also creates a more favourable environment for Russian nuclear threats and attempts to influence European public willingness to support Kyiv.
The objective is not limited to spreading a single false claim. Repeated allegations can foster panic and scepticism among European audiences about continued military, financial and political assistance to Ukraine. A Czech-language publication with an established pro-Russian reputation provides a route for those narratives to circulate within the EU information space.
The strategic cost of any real nuclear programme
A secret nuclear or “dirty” weapons programme would also run directly against Ukraine’s strategic interests. Kyiv depends on maintaining military and financial support from European countries and other allies, while violating the non-proliferation regime could lead to international isolation and weaken external assistance.
Such a programme would additionally give the Kremlin an opportunity to justify further escalation and intensify its nuclear coercion. The relevant issue, however, is not an alleged Ukrainian test supported by a magnitude 2.4 earthquake: it is how effectively unsupported nuclear narratives can be used to undermine confidence in Ukraine and its international partners.
How should European audiences and institutions respond when claims of a Ukrainian nuclear threat are repeated without evidence?
