Warning: This one Text contains disturbing images
Malim was traumatized by what he saw in the western part of Sudan, in Darfur, before he fled across the border to Chad.
"If the people I worked with find out that I showed you these photos and videos, or even recorded them, I'm a dead man," he says as he pulls out his phone to show me gruesome photos of corpses strewn across the town of El Geneina.
We have changed his name for his safety.
Before he left the country, he was part of a group of people tasked with removing corpses from the streets and burying them in mass graves.
Since April, Sudan has been rocked by fierce battles between the paramilitary Rapid Support Force (RSF) and the army, with some of the worst fighting in Darfur, where the RSF originates.
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The photos show dozens of dead bodies, some of them covered with blankets and clothes, others swollen and already rotting.
Malim also showed photographs of destroyed and looted facilities of humanitarian agencies.
"It's a terrible feeling... I felt like they died while they were in a state of fear and terror. "Many of them have been lying dead in the street for over a week," he tells me, visibly upset.
Perhaps the most disturbing was the video he recorded while hiding in the bushes.
It showed bodies being thrown from a truck into a mass grave.
"We went towards the forest cemetery to bury the bodies, but the RSF did not allow us to do so," says Malim, adding that the RSF then ordered them to leave the area.
"On the orders of the RSF, the truck driver was ordered to throw the bodies into the pit.
"They were supposed to be buried according to Muslim customs, to pray for them, but the RSF insisted that they be thrown away as garbage."
No one knows whose bodies are or how these people were killed, but many families who sought refuge in Chad tell us that the RSF specifically targeted young men and boys in West Darfur, forcing them out of hiding and killing them.
The families say that members of non-Arab communities were targeted.
They claim that they were stopped at RSF checkpoints and asked about their ethnicity.
They told us they were too scared to say they were Masalites because they would kill them.
The BBC asked RSF to comment on these allegations, but we have not received a response.
Earlier this week, the RSF denied allegations that it was involved in similar attacks on members of the Masalit community in May.
Malim's account matches the details of a United Nations report released on July 13, which said local residents were forced to dispose of the bodies of at least 87 ethnic Masalites and others allegedly killed by the RSF in a mass grave in West Darfur.
Metadata on the photos and recordings in Malim's phone show they were taken between June 20 and 21, the same date mentioned in the UN report.
Like the UN report, Malim told us that the bodies were buried in an open area known as al-Turab al-Ahmar (Red Soil), west of El Geneina and near a police base.
The UN statement said that some of the people died from untreated injuries.
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In one of Malim's videos, a man is found alive among a pile of dead bodies - flies buzzing around his dry, chapped lips as he tries to speak.
Malim says the man lay there for eight days and had gunshot wounds.
We don't know what happened to that man.
Malim tells us that he made the footage because he wanted to document what was happening in his hometown.
Soon, however, he realized that it was no longer safe to stay in the city.
"I was afraid because they repeatedly searched for people who had mobile phones while they were clearing."
Darfur's Arab and black communities have been at loggerheads for years - with the worst violence erupting two decades ago when non-Arabs took up arms accusing the government of discrimination.
The RSF grew out of the notorious Janjaweed Arab militia, which brutally suppressed the rebellion, killing hundreds of thousands of people.
The group has been accused of widespread atrocities and ethnic killings, described as the first genocide of the 21st century.
Fighting between the RSF and the Sudanese army, which broke out in April, appears to have reignited this conflict.
Last month, the governor of West Darfur was killed shortly after accusing the RSF of genocide against the Masalit people.
This cycle of violence in many parts of Darfur appears to be no accident.
We heard claims that there was a systemic attempt by the RSF and allied Arab militias to target senior figures in black communities like the Masalites, forcing tens of thousands of them to flee to Chad.
RSF says it is a revival of the ethnic violence seen in the 2000s and that it is not involved.
Like thousands of Sudanese who have fled Darfur, Malim has nowhere to return.
His house was burned and all his family's possessions were looted, but most painfully, many of his friends and family are no longer there.
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