South Sudan’s use of improvised air-dropped incendiary weapons has killed and horrifically burned dozens of people, including children, and destroyed civilian infrastructure in Upper Nile state, Human Rights Watch said on Wednesday.
According to the rights body, the government’s use of these weapons in populated areas may amount to war crimes.
Interviewees described the use of improvised incendiary weapons in at least four attacks in Nasir, Longechuk, and Ulang counties, Upper Nile state, which killed at least 58 people and burned others severely. The United Nations Mission in South Sudan (UNMISS), which has a robust mandate to protect civilians, should establish temporary operating bases in high-risk areas and proactively respond to the deteriorating situation. UN Security Council members should urge South Sudan to cease its unlawful attacks and call for the urgent deployment of peacekeeping forces to the affected areas.
“These weapons have killed dozens of people, including children, and left survivors with severe burn injuries causing long-term harm,” said Nyagoah Tut Pur, South Sudan researcher at Human Rights Watch. “The government should immediately stop using indiscriminate incendiary weapons on communities, facilitate safe aid access, and the UN should urgently deploy peacekeepers to the affected areas.”
The government’s aerial bombardments intensified from March 16, 2025, after a March 4 attack on a government military base and Nasir town by armed Nuer youth known as the “White Army” and a March 7 attack by armed men on a UN helicopter that killed a UN crew member and over two dozen South Sudanese soldiers.
On March 17, South Sudan’s information minister said its air force had bombed “so-called White Army areas” and falsely implied that civilians who failed to leave the areas could lawfully be targeted. He revealed that Uganda was providing technical support to the South Sudan People’s Defence Forces (SSPDF), which Uganda has acknowledged.
A Ugandan forces’ spokesperson told Human Rights Watch that their support did not include aerial or ground attacks but could, if requested and they deemed it necessary. The Ugandan forces previously refuted allegations that it had targeted civilians and civilian objects and or used “chemical weapons and barrel bombs.”
Incendiary weapons inflict excruciating burns and other physical injuries, which can lead to psychological harm and lifelong scarring and disability, which can result in social and economic exclusion. They also cause fires that can indiscriminately destroy civilian objects. Use of these weapons in populated areas violates international humanitarian law, and if done with criminal intent, constitutes a war crime.
Protocol III to the Convention on Certain Conventional Weapons explicitly prohibits using air-dropped weapons designed to set fires and burn people in “concentrations of civilians.” While South Sudan is not party to this protocol, its use of these weapons highlights the need to strengthen the international law that governs them.
Eight people interviewed, including witnesses, local responders, and two government officials, described the March 16 attack on Mathiang, in Longechuk county.
Witnesses described “barrels”—improvised incendiary weapons—being dropped from what appeared to be a multi-engine aircraft. A 39-year-old woman said: “It came swooping down, I thought it was going to fall on our compound…. Then we saw it drop barrels. As they dropped, [they caught fire].”
Another woman, 40, woke up feeling “the earth shaking…,” and ran outside … “only to see the village on fire.” She later saw the charred bodies of her neighbors, Khor Ruach Kerjiok, his wife, and their two children under age 10. Another resident said that the burned bodies of two older women aged 60 and above, Nyedier Kuach and Nyeget Kier, were found at home.
A senior health official said that at least 21 people were killed, 3 of whom died while being transported to Ethiopia for treatment. Health workers responding with very limited resources said the victims had extensive burn injuries. One said the burns continued to spread on the patients’ bodies, indicating that a substance that causes burns was used in the attack.
Accounts from witnesses describing what they saw and could smell when the improvised incendiary weapons were dropped, indicate that several types of flammable substances are being used as incendiary agents.
One responder explained how “[t]he area where the [flammable substance] landed was burning for some days, making crackling sounds.” Rain eventually extinguished the fires, “But it still smells … not like gasoline or kerosene,” he said.
Several residential compounds were burned, along with, a responder said, part of the market and two water pumps.
A video posted on social media on March 17 shows a fissure in the ground with visible active fire inside. The video reveals a large, burned area, including several tukuls (homes). Satellite imagery shows a burn scar appeared between March 16 to 17, along with burned tukuls 100 meters northeast of the market.
Two witnesses said at least three women suffered miscarriages or stillbirths following the bombing.
Air-dropped improvised incendiary weapons were also used in Nasir town on March 16 and 19. Two officials said that at least 22 people were killed and dozens of homes burned. Human Rights Watch has also reviewed satellite imagery showing burn scars and burned structures, including a former UNMISS site and dozens of structures along the main road between March 16 and 20.
Interviewees and photographs suggest that an incendiary weapon was also dropped in Kuich in Ulang county on March 21. Three witnesses describe seeing what appeared to be a propeller-driven aircraft drop incendiary substances in barrels.
“[The aircraft] dropped something that was on fire and there was a loud explosion [when it hit the ground] and immediately the surrounding caught fire,” one person said. Everyone started running in different directions.” When he returned to the site, he learned that “people [had been] killed on the spot and many people were seriously injured.”
Four witnesses said the attack killed 15 people, including 3 children, and seriously burned 17 others. A responder in Ulang town described victims, most with burn injuries, “their black skin is coming out. One man who died at the hospital was burned even his teeth. I also saw an older woman in her 70s, she had big blisters.” As of March 30, seven remained in critical condition.
Civilian structures burned included a nutrition center and a healthcare clinic. A guard there, Duop Bichiok Diew, in his 50s, died from burn injuries. Shelters and a market were also destroyed.
Photographs posted on social media on March 24, show several structures reduced to ashes near Sobat River in Kuich. Next to the nutrition center, visible impact sites were still burning. Satellite imagery confirmed that at least a dozen structures burned between March 21 and 22.
Government attacks on populated areas in the three counties, notably with helicopter gunfire and munitions continue, putting civilians at further risk and worsening the humanitarian situation, which already included a cholera outbreak.
Tens of thousands of people have fled, including into Ethiopia. Humanitarian access remains heavily constrained, as aid organizations face violence as well as bureaucratic restrictions.
South Sudan remains under a UN arms embargo prohibiting external military support to the country’s warring parties. Ugandan forces’ participation in the operations violates the embargo. The Security Council should call out Uganda’s violations and ensure renewal of the embargo to protect civilians from unlawful violence, Human Rights Watch said. The council should press South Sudan to ensure that the UN mission can safely operate and approve any requests for additional UN troops.
“As the government of South Sudan continues to show utter disregard for civilians, it is now dropping flaming barrels of fire from the air,” Pur said. “The international community should press the government to end these unlawful attacks and ensure concrete steps to protect civilian lives.”