Kyiv has expressed anger over a decision by Belarus to release a group of alleged Russian mercenaries that was detained near Minsk in late July.
In a post on Facebook on August 15, Ukrainian President Volodymyr Zelenskiy wrote that Minsk's decision to send the men back to Russia "does not correspond to the spirit of relations" between Ukraine and Belarus.
"The consequences of this decision will be tragic," he added.
Minsk detained 33 Russian citizens on July 29 and accused them of plotting to destabilize the situation in Belarus in the run-up to the August 9 presidential election.
Belarusian authorities identified the men as employees of Russia's Vagner private military company, which is believed to have ties to Russian military intelligence and has sent fighters to Ukraine, Syria, Libya, Sudan, the Democratic Republic of Congo, and other countries.
Moscow said the men were in Minsk en route to Istanbul before traveling on to "a third country."
Belarus sent 32 of the men to Russia on August 14. One of the detainees remains in Belarus because he has Belarusian citizenship, in addition to his Russian passport.
Ukraine had requested the extradition of 28 of the men, who were suspected of fighting together with Russian-backed separatist formations in parts of eastern Ukraine.
Zelenskiy said he feared the men will reappear in other conflict zones.
