Analysis by BBC Verify of videos showing fighters boasting of a massacre and aboriginal mocking survivors has identified those liable arsenic seemingly belonging to Sudan's paramilitary Rapid Support Forces (RSF).
The BBC has confirmed that astatine slightest 80 radical died successful the October onslaught connected al-Seriha successful Gezira state, with the UN reporting that the decease toll could beryllium arsenic precocious arsenic 124. An eyewitness told BBC Verify that helium saw unarmed civilians gunned down by fighters astatine adjacent scope arsenic they tried to flee.
The massacre appears to person been prompted by the defection of a elder RSF commandant successful Gezira authorities to the country's equipped forces.
In a connection to the BBC, an RSF spokesperson denied its fighters were progressive successful the killings adding that "the Rapid Support Forces enactment to support civilians and beforehand information and peace, and not to people them."
The brutal conflict, a 20-month powerfulness conflict pitting Sudan's military authorities against their erstwhile RSF allies, has been condemned by quality rights groups for wide atrocities committed by some sides.
Warning: This communicative contains elaborate descriptions of killings and images of dormant bodies, which immoderate readers whitethorn find distressing.
How a defection led to reprisal attacks
On 20 October, the Sudanese subject announced that Abu Keikal, a elder commandant with the RSF successful Gezira state, had defected to them along with a sizeable fig of his forces.
Keikal's determination to instrumentality to the Sudanese army, wherever he'd served earlier the war, was hailed arsenic a large propaganda success, and different RSF soldiers were urged to bash the aforesaid arsenic portion of a wider amnesty offer.
Shortly aft Keikal's defection, fighters launched a bid of astatine slightest 69 reprisal attacks connected towns and villages successful Gezira authorities betwixt 20 October and 4 November, according information recorded by the warfare monitoring organisation Armed Conflict Location and Event Data (ACLED).
BBC Verify has investigated 1 of these attacks successful detail, utilizing eye-witness testimony, outer imagery, video footage and photographs, to recognize what happened.
How a massacre unfolded successful al-Seriha
Mohammad Ismail was attending dawn prayers astatine a section mosque connected 25 October erstwhile helium heard the fighters approaching the outskirts of al-Seriha, a municipality of astir 15,000 people, 90km (60 miles) southbound of Sudan's capital, Khartoum.
He told the BBC that helium ran location to support his household arsenic the unit erupted each around.
Gunmen had climbed up onto a mosque, helium said, and were shooting "at immoderate moved" below.
Many radical were changeable portion trying to escape, helium said. Others were gunned down astatine adjacent scope successful the fields surrounding the town. Many of his household members were among the dead.
Identifying the perpetrators
BBC Verify has obtained a bid of videos filmed by fighters themselves, boasting of their actions and calling retired to Keikal, the erstwhile RSF commander, to spot for himself what they were doing to the radical from his area.
In one, troops with RSF insignia are seen celebrating their onslaught connected the municipality and of sidesplitting locals. The circular insignia seen connected their close shoulders, besides disposable successful immoderate different clips, has a achromatic outline, a curved practice of the Sudanese emblem and a circular logo supra this - the awesome utilized by the RSF.
We person confirmed that this video was filmed successful al-Seriha by comparing buildings and different elements wrong the videos with outer imagery of the town.
In 1 of the videos, a combatant displays his wristwatch to the camera, showing the day arsenic 25 October - and repeating it retired large - the day of the massacre successful al-Seriha.
Mr Ismail besides told the BBC that erstwhile they came to the town, helium recognised immoderate of the fighters progressive successful the onslaught arsenic erstwhile residents who had signed up to combat with the RSF.
He besides said helium saw 2 commanders known to beryllium elder RSF leaders successful the area. BBC Verify enactment images of immoderate RSF fighters done facial designation bundle successful an effort to place the individuals, but these searches returned nary matches.
The troops near locals successful nary uncertainty that the massacre had been carried retired successful effect to Keikal's defection.
In 1 video a defender says successful Arabic: "Keikal … look these are your people."
We were capable to lucifer landmarks successful this video specified arsenic trees and the signifier of adjacent buildings seen successful the videos to outer images of al-Seriha.
In a further video - which couldn't beryllium geolocated but archetypal appeared online connected 26 October - men wearing subject fatigues with RSF insignia speech astir Keikal's defection and notation to "traitors" successful Gezira state. They specifically mentioned al- Seriha, adding that the municipality would get what it deserved.
At respective points successful the video, they notation to themselves utilizing the Arabic connection "ashawis" meaning the "brave ones", a word utilized by RSF fighters to place themselves.
When BBC Verify approached the RSF for comment, they denied those seen successful the clips were their troops. "You tin easy get a Rapid Support Forces azygous and deterioration it… past perpetrate crimes against civilians, to criminalise the Rapid Support Forces," a spokesperson for the radical said.
While it's not imaginable to regularisation this out, the BBC has seen 3 abstracted videos filmed by the fighters themselves, successful which RSF insignia tin beryllium seen connected the uniforms of those involved.
A study by Human Rights Watch into the attacks connected al-Sehira and different towns successful Gezira authorities since Keikal's defection connected 20 October, identified the RSF arsenic the perpetrators.
On 29 October, the UN issued a connection condemning the killings successful al-Seriha and different towns successful Gezira authorities and identifying the RSF arsenic being liable for these attacks.
How galore civilians were killed?
The BBC has obtained 4 abstracted videos of the aftermath of the onslaught connected al-Seriha. They are precise graphic and amusement bodies lined up successful the courtyard of a mosque, covered with shrouds and blankets. The earliest versions of these videos appeared online connected 26 October.
BBC Verify has established that the representation beneath was taken successful the courtyard of the mosque by matching cardinal features, including the alloy gross and a outer crockery successful the background, to an representation of the mosque from Google maps.
BBC Verify studied the video and photographic evidence, counting astatine slightest 82 bodies laid retired connected beds oregon connected the floor.
The UN has said that 124 radical died the reprisal killings successful al-Seriha. A section civilian nine group, the Gezira Congress, says that fig could beryllium arsenic precocious arsenic 140.
Another portion of grounds uncovered by the BBC Verify probe is the quality of freshly-dug world mounds successful the municipality cemetery.
Mr Ismail had told america that a wide sedate had been dug successful the graveyard.
In outer photos captured aft the attack, these mounds tin beryllium seen successful a antecedently unused conception of the cemetery. They are not contiguous successful outer images taken successful May.
Nathaniel Raymond, Executive Director astatine the Yale's Humanitarian Research Lab told the BBC that successful a abstracted representation taken connected 30 October, the graves look to person been precocious dug fixed the chiseled signifier of the mounds and the colour of the surrounding earth. In the graphic above, we've shown a outer representation from 6 December which much intelligibly shows the cemetery.
"These 2 indicators archer america that the mounds had not been determination for apt much than a fewer days due to the fact that the edges of the mounds implicit clip volition smoothen and go much blurry due to the fact that of upwind and dust," helium said.
While the BBC cannot verify however galore radical whitethorn beryllium buried successful the caller conception of the cemetery, the size of the world mounds measured against the adjacent achromatic gathering suggests galore bodies could person been buried there.
Survivors taken for ransom
Once the archetypal shooting was implicit and the troops had taken power of the town, the surviving men were rounded up and detained.
BBC Verify has obtained videos of these detentions and abductions.
In one, astatine slightest 60 radical tin beryllium seen sitting oregon lasting against a partition being watched by the equipped fighters.
Some of the captives look to beryllium elderly, and galore are wearing what look to beryllium bloodstained achromatic robes.
At 1 constituent successful the video, the fighters taunt their captives, calling them dogs and making carnal noises.
"Say baa, you dogs, accidental baa, accidental baa. You situation again to instrumentality up arms, don't messiness with the Rapid Support Forces."
BBC Verify has confirmed this was filmed astatine the north-western portion of the municipality by matching distinctive features shown connected outer maps. In particular, determination is simply a corrugated robust operation disposable which tin besides beryllium seen connected outer imagery captured connected 30 October.
Others are seen walking successful a enactment with their arms raised. Footage aboriginal shows the fighters mocking their captives, with residents forced to marque carnal noises portion the fighters laughter and look on.
Another radical of men were aboriginal marched past the fighters with their hands down their backs.
As the radical record past, 1 combatant recognisable from earlier clips again mocks the men.
"Did we decision al-Seriha," the combatant asks the captives, earlier repeatedly saying: "Did we bash well?"
Elmubir Mahmoud, secretary-general of the Gezira Congress, told the BBC the fighters took 150 hostages distant with them aft they near the town. He said that astatine slightest 11 captives - including a three-year-old miss - person since been killed. BBC Verify cannot corroborate this.
But grounds fixed to america by municipality nonmigratory Mohammad Ismail suggests that survivors were forced to wage ransoms for the merchandise of their household members. He said their captors had demanded betwixt US$100 and US$1,000.
The activities of the RSF and the Sudanese subject successful Gezira authorities person attracted planetary condemnation, with the UN and quality rights groups expressing outrage.
In a statement, the US Ambassador to the UN Linda Thomas-Greenfield urged countries to cease providing arms to some sides of the war. She said supplies were prolonging the conflict.
"The radical of Sudan person endured hell," she said. "They merit safety, dignity, and justice. They merit to live."
Additional reporting by Mohanad Hashim. Graphics by Mesut Ersoz.