A little earlier, the African leaders went to the site of the mass grave in the town of Bucha, which lies just outside of Kyiv.
The South African presidency has tweeted a few videos of them arriving and taking part in a short remembrance ceremony.
There are 458 people buried in the mass grave who were killed at the start of the war.
Ukraine says it has uncovered multiple mass graves in Bucha, Borodyanka and other towns near the capital Kyiv that were briefly seized by Russian troops.