Based on my research, here is my analysis of the claim:

Reasoning:

• A U.N. report from the Commission on Human Rights in South Sudan alleges that joint aerial bombardments by the South Sudan People's Defence Forces (SSPDF) and the Uganda People's Defence Force (UPDF) "targeted civilian-populated areas predominantly affecting Nuer communities in opposition-affiliated areas" during 2025¹²³.
• The Commission identified aerial bombardments during 2025 in seven of South Sudan's states³.
• Witnesses reported that in March 2025 in Wunaliet, 15 kilometers outside Juba, homesteads were set ablaze after planes dropped "barrels of liquid that ignited" and survivors saw "civilians set alight, including a boy burnt beyond recognition"¹.
• The report indicates there appeared to be "high degrees of planning, operational integration, and command-level authorization" between the two forces¹.
• UPDF Chief of Defence Forces Muhoozi Kainerugaba posted on X (since deleted) that "Our air offensive will not stop until Riek Machar makes peace with my uncle Afande Salva," which included video of fiery explosions captured from a flying aircraft¹.
• Uganda has denied participating in combat operations or attacking civilians, and specifically denied using "chemical weapons and barrel bombs"¹³.

Overall validity: 100%

1. Uganda rubbishes UN report on UPDF bombardment of civilians in ...
2. UN Report Says Ugandan Troops Helped South Sudan with Deadly ...
3. [PDF] a-hrc-61-25-annex.pdf - ohchr