KYIV, Ukraine (AP) — Russian forces thwarted an attempt at another cross-border incursion by Ukraine into southwestern Russia, a local official reported Sunday, months after Kyiv staged a bold assault on its nuclear-armed enemy that Moscow is still struggling to halt.

An “armed group” sought Sunday to breach the border between Ukraine and Russia’s Bryansk region, its governor, Aleksandr Bogomaz, said but was beaten back. Bogomaz did not clarify whether Ukrainian soldiers carried out the alleged attack, but claimed on Sunday evening that the situation was “stable and under control" by the Russian military.

There was no immediate acknowledgement or response from Ukrainian officials.

The region neighbors Kursk province, where Ukraine launched a surprise push on Aug. 6 that rattled the Kremlin and constituted the largest attack on Russia since World War II. Hundreds of Russian prisoners were blindfolded and ferried away in trucks in the opening moments of the lightning advance, and Ukraine’s battle-hardened units swiftly pressed on across hundreds of square miles (square kilometers) of territory.

Responsibility for previous incursions into Russia’s Belgorod and Bryansk regions have been claimed by two murky groups: the Russian Volunteer Corps and the Freedom of Russia Legion.

Russian officials and state media have sought to downplay the significance of Kyiv’s thunderous run in Kursk, but the country’s forces have so far been unable to dislodge Ukrainian troops from the province. Western officials have speculated that Moscow may send troops from North Korea to bolster its effort to do so, stoking the almost three-year war and bringing geopolitical consequences as far away as the Indo-Pacific region.

Russian lawmakers Thursday ratified a pact with Pyongyang envisioning mutual military assistance, a move that comes as the U.S. confirmed the deployment of 3,000 North Korean troops to Russia.

North Korean units were detected Wednesday in Kursk, according to Ukraine’s Main Intelligence Directorate, known by its acronym GUR. The soldiers had undergone several weeks of training at bases in eastern Russia and had been equipped with clothes for the upcoming winter, GUR said in a statement late Thursday. It did not provide evidence for its claims.