MOSCOW, May 30, 2025 (BSS/AFP) - Russia said Thursday it had evidence that Serbian defence companies were supplying Ukraine with ammunition, in a rare rebuke of a country Moscow considers an ally.

The Balkan nation with close historical links to Russia has maintained an official policy of neutrality throughout Moscow's three-year offensive on Ukraine and has denied arming either side.

President Aleksandar Vucic said however that a joint working group had been started to look into the accusations.

Russia spoke out after media outlets, including the Financial Times, reported that hundreds of millions of dollars worth of Serbian ammunition have indirectly reached Kyiv via contracts with third countries.

In a statement headlined "The Serbian military industry is trying to stab Russia in the back", Russia's SVR foreign intelligence service alleged that Serbia's largest defence companies were involved in covert arms exports.

"A simple scheme involving fake end-user certificates and intermediary countries is being used to cover up these anti-Russian activities," it said.

Serbian companies have produced hundreds of thousands of shells and a "million rounds of ammunition for small weapons" that have been used to "kill and maim Russian servicemen and the civilian population of Russia", it alleged.

Among the companies listed were Krusik and Yugoimport SDPR -- both owned by the Serbian government -- as well as Zenitprom, Sofag, Reyer DTI, Sloboda and Prvi Partizan.

"In Russia-friendly Serbia, the nation's largest defence companies are participating in a conveyor belt of death," it said.

The accusation comes just three days after the two countries extended a gas deal that sees Serbia pay below-market prices for Russian gas imports.

Serbia has tried to balance its foreign policy interests between Russia and the European Union, which it is seeking to join, but has been accused by the West of trying to play both sides.

Brussels has warned that Serbia's ties with Russia are incompatible with EU membership.

Vucic, one of the few European leaders to visit Moscow this month for Russia's World War II commemorations, said he had discussed the issue with Russian President Vladimir Putin.

He did not give details of the talks, but said: "We have formed a working group, together with Russian partners, to establish the facts." he told Serbia's public RTS broadcaster on Thursday.

Vucic stressed that Serbia's arms factories "must work" and added that the sector employed some 24,000 people.

"But I will certainly issue an order and a warning that wherever there is suspicion of abuse of the so-called end-users ... that we know about it and that such contracts are not implemented," he told the RTS public broadcaster.