The Interfax News Agency, which is based in Russia, reported that a member of the Ukrainian negotiating team was suspected of treason. There has been no official confirmation of the report.
The Kyiv Independent indicated that the incident took place but offered few specifics.
Interfax based its report on a Telegram post from Ukrainian parliamentarian Oleksiy Honcharenko.
The post said the killing occurred during the first round of peace talks held in Belarus.
“During an attempt to detain Denys Kyreyev, a member of the Ukrainian negotiating delegation, the Ukrainian Security Service shot and killed him. He was suspected of high treason,” Honcharenko wrote on Telegram, according to Interfax.
“The [Ukrainian Security Service] had clear evidence of Kyreyev’s high treason, including his telephone talks,” Honcharenko said, citing sources he did not name.
As Russian forces continued their conquest of Ukrainian cities in the south but could not make similar progress in the north, Ukrainian President Volodymyr Zelenskyy spoke via video to protesters in multiple European cities, according to USA Today.
“If we fall, you fall,” he said on Friday.
Zelenskyy has so far been rebuffed by European countries in his efforts to secure active military support, although nations have slapped sanctions on Russia and continue to ship military hardware to Ukraine.
In the southern city of Mariupol, Russia was accused of violating a cease-fire that had been arranged to allow civilians to flee.
“The Russian side is not holding to the ceasefire and has continued firing on Mariupol itself and on its surrounding area,” said Kyrylo Tymoshenko, deputy head of the Ukrainian president’s office.
“Talks with the Russian Federation are ongoing regarding setting up a ceasefire and ensuring a safe humanitarian corridor.”
On Saturday, Zelenskyy begged a group of U.S. lawmakers for more aid and weapons, including planes.