South Sudanese troops have moved in Heglig oil field It comes under an unprecedented deal with warring parties in neighboring Sudan to protect vital energy infrastructure from the country’s civil war.

Wednesday’s deployment comes after the paramilitary Rapid Support Forces (RSF) seized strategic locations on December 8, forcing the government-aligned Sudanese Armed Forces (SAF) to retreat across the border into South Sudan, where they reportedly handed over their weapons.

The agreement aims to shield the facility from combat operations as fighting intensifies in Sudan’s Kordofan region, threatening both countries’ main source of revenue.

Official sources in the Sudanese government told Al Jazeera that there have been high-level contacts between the leaders of Sudan and South Sudan since the beginning of this week when the Forces Without Borders launched an attack on the “Heglig” area. The two sides reached an understanding to ensure the evacuation of oil field workers and avoid military confrontation to ensure that the oil field and its facilities were not damaged and destroyed, in which tribal leaders also played a role.

The deployment of South Sudanese troops is based on the previously signed oil and security cooperation agreement between Khartoum and Juba, which provides for the protection of South Sudanese oil fields, pipelines and central pumping stations, in addition to power interconnection projects and strengthening cooperation in the energy sector.

A new factor is the involvement of Doctors Without Borders.

South Sudan People’s Defense Forces chief of staff Paul South said in Heglig that the troops were joining under a “tripartite agreement” involving President Salva Kiir, Sudanese Armed Forces Commander Abdel Fattah al-Burhan and Médecins Sans Frontières leader Mohamed Hamdan Dagalo, better known as Hemedi, state broadcaster SSBC News reported.

The agreement requires Sudanese troops to withdraw from the area.

South Sudan emphasized that the South Sudanese army will maintain strict neutrality.

“The first goal is to completely eliminate any combat operations in the Heglig oil field” because it “represents the economic lifeline not only of South Sudan but also of Sudan,” he said.

The deployment follows a deadly drone strike on Tuesday night that killed dozens of people, including three South Sudanese soldiers.

The Singapore Armed Forces confirmed the use of drones to target Doctors Without Borders fighters at the facility, but the exact death toll remains unclear. Local media reported that seven tribal leaders and numerous Médecins Sans Frontières personnel were killed in the attack.

According to officials in South Sudan’s Unity State, about 3,900 Sudanese soldiers entered South Sudan’s Lubkona County after evacuating Heglig to hand over tanks, armored vehicles and artillery to South Sudanese authorities.

Thousands of civilians have also fled across the border since Sunday.

Heglig has a central processing facility capable of processing up to 130,000 barrels per day of South Sudanese crude oil, which will be exported via the Sudan pipeline. The site also includes Block 6, Sudan’s largest producing oil field.

Jan Pospisil, a South Sudan expert at Coventry University, explained the strategic considerations behind this unusual arrangement.

“From the Sudanese Armed Forces’ perspective, they don’t want MSF to find another possible source of revenue, and from their perspective it’s better for South Sudan to control the area,” he told Al Jazeera.

He added that Médecins Sans Frontières “cannot really defend against SAF airstrikes, as we saw with this drone strike, and they don’t need the money right now”.

The capture of Hegrig marks the latest advance for Médecins Sans Frontières in the conflict Shift of focus From Darfur to the vast Kordofan region. In October, with the fall of El Fasher, paramilitary forces took full control of Darfur, sparking international alarm over mass atrocities.

Activists in the Tavira refugee camp told Al Jazeera that refugees continued to arrive, with some forced to sleep outdoors due to a lack of resources.

United Nations High Commissioner for Human Rights Volker Turk repeat He warned last week that he was “extremely concerned that we may see a repeat of El Fasher’s atrocities in Kordofan” as Doctors Without Borders made advances in the region.

His warning was echoed by the Global Center for the Responsibility to Protect, with executive director Savita Bonndi stressing that Sudan faces “one of the worst atrocity crises in the world” and that civilians are suffering “unimaginable harm, while the international community has failed to respond”.

Fighting has triggered displacement, with the International Organization for Migration reporting that more than 1,000 people fled South Kordofan province in just two days this week as fighting intensified around the state capital, Kadugli.

In El Fasher, the Sudanese Doctors Network reported this week that Médecins Sans Frontières holds more than 19,000 detainees in Darfur prisons, including 73 medical staff.

The medical advocacy group said cholera outbreaks are killing people due to overcrowding and a lack of adequate health care, with more than four people dying each week due to medical negligence.