In December, 24-year-old Osman Arbab* and his younger brother were sitting on a bus just outside Atbara, Sudan, when military intelligence stopped him and asked which of the passengers were from Darfur or Kordofan.

The two men are originally from Kordofan, although they have not lived there for years, and were on the bus with all the other young men who came from the two places.

Military intelligence officials told them everything they were accused of spying for the paramilitary group Rapid Support Forces (RSF) and took them to a facility in Atbara, northeastern Sudan.

Arbab and his brother were beaten with sticks for six days to extract confessions from them. They were recorded together so everyone could see and hear what happened to their brother.

When the batons didn’t work, on the seventh day their interrogators connected them to electric cables and began giving them electric shocks.

Arbab remembers seeing his brother screaming, unable to do anything for him.

“We will not make it”

“My brother [has diabetes]and I remember thinking that we can’t get out of here,” Arbab told Al Jazeera.

“I thought, ‘My brother is going to die.’ … They’re going to kill us.’”

The army appears to be cracking down on people from regions where its rivals, the RSF, have support, accusing them of being RSF “sleeper cells.”

The people caught in these dragnets across the country were victims of enforced disappearances and often torture, with little or no evidence presented against them

At least dozens were extrajudicially executed, according to videos confirmed by Al Jazeera.

Survivors and local observers said security forces mainly targeted people from Kordofan in South Sudan or Darfur in the west, which are considered RSF strongholds. In some regions, civilians belonging to nomadic “Arab” tribes may be at greater risk because the RSF recruits extensively from their communities.

Arbab also thought he would die – if not from torture, then from the terrible prison conditions. He said his room was freezing, he was given little water and was forced to pay for his food. After surviving for 12 days, an official asked for a bribe to release him.

“I gave $50 for myself and $50 for my brother, and the next morning they finally let us go,” Arbab told Al Jazeera.

Even army soldiers were killed if anyone suspected they were loyal to the RSF. In Kordofan, most army battalions are made up of local “non-Arab” Nubians and local “Arabs”.

There is a widespread perception that “Arab” army officers secretly support the RSF, fueling fears that the military could fracture along ethnic lines.

The army reportedly executed 10 soldiers from nomadic “Arab” tribes in Dilling, South Kordofan this month, accusing them of collaborating with the RSF.

One of the soldiers was tied to a ladder and hung by his feet as crowds cheered his execution, according to a video on social media confirmed by Al Jazeera. A photo of the aftermath shows that the victim appeared to have been tortured to death. Local observers and activists described the killing as a “crucifixion.”

Ethnic tension

“There have always been tensions in South Kordofan based on ethnic and tribal boundaries, even in the army,” said Hafiz Mohamad, a Sudanese researcher from South Kordofan.

Mohamad told Al Jazeera that in previous civil wars in Sudan, Nuba soldiers and civilians were accused of working with mainly “non-Arab” rebel groups. Now things have changed and “Arabs” are being targeted.

Ethnic tensions are also increasing in the north and east of Sudan.

On December 16, the army withdrew from Wad Madani, Sudan’s second largest city, after the RSF captured it.

The last act was the military executed Dozens of civilians belonging to “Arab” and “non-Arab” tribes from Darfur said in a video shared by pro-army reports confirmed by Al Jazeera.

Al Jazeera sent messages to army spokesman Nabil Abdullah asking about the mass executions and allegations of arbitrary arrests and torture on ethnic grounds, but received no response at the time of publication.

Mohamad Osman, Sudan researcher for Human Rights Watch (HRW), told Al Jazeera that the army’s decision to arm civilians could lead to more ethnically motivated killings.

He said the army was stoking ethnic divisions to boost recruitment and giving the RSF a pretext for retaliation along ethnic lines as happened in Darfur. Videos emerged on social media on Friday showing RSF fighters arresting and killing unarmed men in Gezira state, which they had fully captured after capturing the capital Wad Madani last month.

Many victims were reportedly accused of collaborating with the army.

“Who is a civilian and who is a combatant will be unclear,” Osman told Al Jazeera. “And including civilians as combatants… will help the RSF’s discourse when they claim that they are not attacking civilians but fighters.”

Counterproductive

In the early 2000s, thousands of people fled Darfur to the northern and eastern states. At that time, “Arab” tribal militias – backed by the army and later renamed the RSF – attacked civilians based on their ethnicity.

According to HRW, they committed a roundup Executions against “non-Arabs” and burned down their villages, often believing they were supporting rebel groups. Two decades later, the army accuses the survivors of these attacks of supporting the RSF.

Muzan Mabrooka*, a young woman from a “non-Arab” tribe in Darfur, said she and her male colleague were arrested in June and accused of being RSF spies.

They were stopped in Gadarif, a state in eastern Sudan, taken to a detention center and interrogated. Her male colleague was severely beaten, Mabrooka said.

“When they finished investigating me, they told me to leave. But I claimed that my colleague was my husband and I would not leave him. I was afraid that if I left they would really hurt him,” Mabrooka told Al Jazeera.

Mabrooka’s colleague was eventually released that day, but two of her friends were later kidnapped and tortured in Kassala, a state in eastern Sudan. She said they were also released but were too afraid to talk about what happened to them. Many others remain missing, according to local observers.

Jehanne Henry, a human rights expert on Sudan and non-resident fellow at the Middle East Institute, said the army was doing itself a disservice by targeting people based on their ethnicity.

“Military intelligence could lead people to look for other allies – if not RSF, then perhaps groups that get along with RSF – which is politically very dangerous for the Sudanese armed forces,” Henry said. “The army just made one mistake after another.”

Mabrooka added that regardless of the context, it is always assumed that civilians from Kordofan and Darfur were conspiring against the army. She criticized the army for pretending to protect civilians while committing many serious violations.

“It doesn’t matter who has supported the RSF in the past or not,” Mabrooka told Al Jazeera. “All tribes [from Darfur and Kordofan] are now being targeted.”

*Names have been changed to protect individuals.

Note to readers: The terms “Arab” and “non-Arab” are sensitive terms in many regions of Sudan. Both communities are black and Muslim and have intermarried for centuries. The labels usually refer to communal ways of life. “Arabs” are traditionally shepherds and camel herders, while “non-Arabs” are sedentary farmers.