Between February and August 2020, a large-scale war between Lou Nuer and Bor Dinka militias against Murle militias left at least 1,000 people dead and 150,000 displaced. The conflict took place in the Greater Jonglei region, comprising Jonglei State and the Greater Pibor Administrative Area. The conflict was one of the largest inter-communal violent conflicts since the signing of the R-ARCSS peace agreement.

Background The areas of Jonglei and Greater Pibor Administrative Area (GPAA) are located in central and eastern South Sudan, and have been hubs of conflict between local Nuer, Dinka, and Murle communities over land rights and herding. Local self-defense and cattle-raiding militias formed by these groups have been co-opted by warring parties throughout the South Sudanese Civil War in 2013 and 2018. The Bor Dinka are the largest ethnic group in the region, and live in Bor South county, Twic East County, and Duk County. Lou Nuer and Murle are both sizable minorities in the region; the Lou Nuer live in Nyirol, Akobo, and Uror, and the Murle live in Pibor County.

The Sudan People's Liberation Army (SPLA), the rebel group that fight the Sudanese government until South Sudanese independence, when it became the de facto South Sudanese army, historically supported the Bor Dinka, as John Garang was a Bor Dinka. The Nuer White Army, allied at times with the main rebel group Sudan People's Liberation Movement-in-Opposition (SPLM-IO), was also present in Jonglei, and had sizable Nuer support. The predominantly-Murle Cobra faction led by David Yau Yau launched a rebellion in 2012, which after negotiations led to the creation of the majority-Murle Greater Pibor Administrative Area (GPAA), which is considered at times to be part of the Greater Jonglei area.

The South Sudanese Civil War officially ended in 2018, but ethnic violence continued throughout Greater Jonglei between the Bor Dinka, Lou Nuer, and Murle. Despite the decrease in attacks and massacres by government forces and opposition militias, violence by community-based militias significantly increased and became the dominant cause of violence in Greater Jonglei. Rank and file members of the South Sudanese Army (SSPDF) and the SPLM-IO participated in the campaign.

Prelude Between December 2019 and January 2020, Lou Nuer community militias gathered in Walgak to discuss an impending attack on Murle communities in the following months. Further meetings took place in February 2020, where the militia leaders discussed which specific Murle communities and cattle camps to raid. Throughout this time, 10,000 Lou Nuer militiamen were mobilized in preparation for the raids, some blessed by a Nuer prophet. These militias were largely part of the Nuer White Army and the Dinka militias comprised some fighters in the Dinka militia Titbaai.

In February 2020, top Dinka and Nuer community leaders met in Poktap to set aside their differences and conduct joint operations against the Murle. The primary grievance both groups had against the Murle was that Murle communities, protected by armed Murle militias, were expanding their cattle-grazing areas into Lou Nuer and Bor Dinka territory. In the lead-up to President Kiir's announcement of the dissolution of Boma State despite keeping the GPAA, small groups of Murle men launched incursions into Nuer and Dinka communities (which were already mobilizing against the Murle).

Some of these incursions were armed attacks. These incursions took place between January and February 2020 in the Lou Nuer areas of Akobo, Nyirol, and Uror and in the Bor Dinka areas of Duk and Twic East.

War

First offensive (February 18-March 3) On February 18, Lou Nuer fighters gathered along the Nanaam River at Likuangole. The following day, they attacked Lokoromach payam and Gie payam and villages in those payams. Murle groups attempted to repel the Lou Nuer attacks at the village of Kirmith, but were defeated with heavy casualties on February 26. Around 800 Murle participated in the defense of the town, and dozens of me from the Lango age-set group were killed in the defense. Lou Nuer groups then took control of Likuangole and surrounding villages without resistance, probing villages along the Lilibok river until they retreated into their home counties on March 3.

At the same time as the February attacks by the Lou Nuer, Bor Dinka militiamen and Gawaar Nuer militiamen attacked the village of Bich-Bich on February 18, and then attacked the village of Thangnyang. A second group of allied Dinka-Gawaar Nuer militiamen attacked the village of Pakeny and then several more villages along the Nanaam river. Outnumbered Murle militiamen put up resistance against the Dinka-Gawaar Nuer attackers at Pakeny on February 25, forcing the former to flee the following day to Manyabol. Manyabol was a hub for Murle civilians fleeing the violence, and those who had heard about an impending offensive on February 27 fled up the Lothila river. They were chased by the Dinka-Gawaar Nuer attackers, and many women and children were abducted. Manyabol remained under Dinka-Gawaar Nuer control until March 3.

Around 15,000 Lou Nuer, Bor Dinka, and Gawaar Nuer militiamen participated in the attacks in February and March. At least 51 settlements were destroyed or attacked between February 18 and March 3. Both attacking militia groups abducted women and children, and stole cattle from the Murle. The exact number of casualties is not known from these attacks. A June 2020 United Nations report said that hundreds of civilians were killed, thousands of women and children abducted, and thousands of people displaced in the February attacks. A March 2021 United Nations report said that 346 total people, fighters and civilians, were killed. Another U.N. report in May 2020 said 220 civilians were killed.

OCHA in South Sudan, in its February 2020 report, said that 16,000 people were displaced in Akobo and Nyirol counties and 10,000 affected in Pibor. The majority of displaced civilians in Pibor took refuge in the UNMISS base in the town. The Red Cross treated at least 70 patients for gunshot wounds in Akobo, Ganyliel, and Juba. Médecins Sans Frontières' hospital in Lankien received 68 wounded. Katja Lorenz, the deputy director of the Red Cross in South Sudan, said that the majority of casualties could not be treated by the Red Cross, even by air, because of the threat of being shot at.

Between March 3 and May 16, little to no clashes occurred between the two sides, partially due to the COVID-19 pandemic. Starting on April 22, UNMISS went on a COVID-19 awareness campaign in Jonglei and the GPAA. Restrictions imposed on movement due to COVID-19 prevented authorities from identifying or retrieving civilians abducted during the first offensive. The Human Rights Division of UNMISS (HRD) reported that between April and June 2020, the number of civilians affected by violence across all of South Sudan decreased by 8% despite a 52% increase in the number of violent incidents. The war in Greater Jonglei comprised 20% of these incidents.

Pieri offensive (May 2020) Murle militiamen organized themselves in May 2020 for a retaliatory attack on the Lou Nuer town of Pieri, under the control of the Riek Machar faction of SPLM-IO. Prior to this attack, Murle militiamen had a shaman pray over them, and some ethnic Murle SSPDF soldiers from the Eagle Battalion and former Cobra Faction soldiers took part in the mobilization. ACLED said that National Security Service (NSS) and SSPDF military intelligence provided weapons and intelligence to the Murle prior to the Pieri offensive. This local shaman was an influential religious-political leader known as a "red chief", and he sanctioned the Pieri attack because he had family members killed in the February attacks. Murle politicians publicly and privately supported the attack, and a Murle colonel was killed during the offensive. Many of the militiamen participated with the goal of retrieving abducted Murle women and children. About 7,000 Murle militiamen, almost entirely from Likuangole and the surrounding area participated in the Pieri attack.

On the morning of May 16, Murle militiamen attacked over 28 villages over a 25 kilometer radius in Uror County, surprising the Lou Nuer. The Murle offensive was very well-coordinated and many Lou Nuer defenders were killed. By the early afternoon, Lou Nuer soldiers in the SSPDF's 22nd Brigade in Waat and SPLM-IO fighters in Walgak, along with other Lou Nuer militiamen from Akobo East, Lankien, Motot, and Walgak arrived in Pieri to reinforce the Lou Nuer there. These reinforcements reversed the Murle offensive, and the Murle fighters were forced to retreat back to the GPAA. Murle fighters who became separated during the retreat were ambushed and killed between May 17 and 20.

The HRD reported that at least 121 civilians were killed during the Murle attack on Lou Nuer villages near Pieri. Another 24 were injured, and sixteen women and children were abducted. At least 400 fighters were killed during the May 16 attack and its aftermath. The March 2021 U.N. report said that only 183 people were killed, both fighters and civilians, in the Pieri offensive. Al Jazeera said that 287 people had been killed, and at least 300 more had been injured. A January 2021 United Nations report said 211 civilians were killed and 300 were injured, along with 25 women and 48 children abducted. A June 2020 U.N. report said that hundreds were killed during the offensive, and thousands of civilians were displaced. Médecins Sans Frontières said on May 19 that they had treated 56 injuries from the Pieri area at the hospital in Lankien, but estimated many more could be dead and over 100 wounded in and around Pieri. The injured in Pieri were likely unable to access treatment, increasing the mortality rate from injuries. Two MSF personnel, of three present in Pieri, were injured in the offensive. One MSF worker was killed, along with two members of an unnamed humanitarian organization.

Maruwa Hills offensive (June–August) In response to the Pieri offensive by the Murle on May 16, Dinka militias from Duk and Twic East along with Gawaar Nuer militias from Fangak, Ayod, and Piegi mobilized in Anyidi. Bor Dinka militias joined this mobilization as well. Very few Lou Nuer militiamen took part in this mobilization and subsequent attacks for more than a month due to the heavy losses sustained in Pieri. About 17,000 Dinka, Gawaar Nuer, and Lou Nuer took part in these attacks. In June, Dinka and Gawaar Nuer fighters declared a no-fly zone over the GPAA, threatening to shoot down a UNMISS helicopter.

A Murle raid in May, involving 9,000 Murle militiamen, took place in Padoy, Akobo County, which is a Lou Nuer area. At least 370 people were killed in this massacre, and another 50 were injured. Some Lou Nuer tried to defend themselves but did not succeed.

The first attacks began on Gumuruk and Manyabol, which were besieged by the Dinka-Gawaar Nuer alliance between June 11 and July 7. In an attack on Gumuruk, the local hospital was burnt and food storage facilities were burned. Almost all of Gumuruk's population fled, and 140 women and children were kidnapped, along with 175,000 head of cattle. On July 7, the Dinka-Gawaar Nuer alliance pushed further east, engaging in battle with Murle militias in the Maruwa Hills east of Pibor and in the town of Verteth. Both Verteth and the Maruwa Hills are located deep in the GPAA. The Dinka and Gawaar Nuer abducted women, children, and cattle on their march to the Maruwa Hills. The march to the Maruwa Hills was reinforced by a Lou Nuer offensive along the Nanaam river and Likuangole that began on July 8 and lasted till July 10. The Lou Nuer destroyed several villages and killed some civilians. Like their Dinka-Gawaar Nuer allies, the Lou Nuer abducted women, children, and cattle. Many women were sexually abused and raped by the attackers.