Twelve-year-old Abdiwahab - not his real name - sobs as he recounts what happened to him as he escaped from the western Sudanese city of el-Fasher.

The young boy left el-Fasher on Sunday as it fell to the paramilitary Rapid Support Forces (RSF), the paramilitary group that has been fighting a two-and-a-half-year civil war against the army.

In a video received by the BBC, his face reflects deep sorrow and fatigue, his voice low as he describes being assaulted many times by RSF fighters.

Fearing reprisal attacks from RSF fighters, Abdiwahab joined a wave of people - including some of his family - trying to flee.

The UN estimates that 60,000 have managed to escape el-Fasher, with many narrating horrendous accounts of atrocities, including rape.

After three days of walking, Abdiwahab reached the relative safety of Tawila - an 80km (50-mile) journey - but he arrived alone. I left the city with my father and siblings, but because of the chaos we were separated, I came to Tawila alone, he said.

On his way, he was assaulted and accused of espionage. I walked along the road, and [the RSF] caught me many times. They beat me, saying, 'this little boy is a spy.' This reflects the broader issue of young boys facing severe risks of violence and arbitrary arrest amidst the ongoing conflict.

Abdiwahab also mentioned that RSF fighters had previously taken his mother and sister about a month ago, and he has no information about their fate. Ali, a volunteer aid worker who filmed Abdiwahab's testimony, noted that the boy was traumatized, fearing any sign of RSF vehicles at night.

In the temporary camp where Abdiwahab has found refuge, many new arrivals bear stories of suffering and loss, with some children having lost their parents during the treacherous journey.

The aid workers in Tawila are overwhelmed by the overwhelming number of people needing help. Survivors recount heart-wrenching tales of passing dead bodies on their way to safety, adding that the situation remains critical as humanitarian organizations find it increasingly dangerous to operate in the area.

As the conflict continues and reports of mass killings emerge, thousands remain trapped in el-Fasher, with the UN estimating that over 260,000 civilians are caught in dire conditions, exacerbated by famine and lack of healthcare. Relief efforts are hampered by the ongoing threat of violence from militant groups.