The Associated Press had rare access to a refugee camp where people from Mali alleged abuses by Africa Corps, a new military unit under Russian control.

Africa Corps earlier this year replaced the Russian mercenary group Wagner, which had been helping the military governments of Mali, Burkina Faso and Niger combat militants linked to al-Qaida and the Islamic State group in West Africa’s Sahel region.

The region has become the deadliest place in the world for extremism.

Civilians like the refugees say they are caught in the fighting. The United Nations has reported abuses on all sides. But the allegations against Africa Corps are new, and the AP is reporting them for the first time.

The AP spoke with 34 refugees in and near the camp in neighboring Mauritania. They alleged abuses including rapes and beheadings.

One 14-year-old girl lay motionless in a makeshift health clinic, her eyes glazed and her mouth open. Medical workers hurried around her. It was the last moment to save her life, said Bethsabee Djoman Elidje, the clinic's women's health manager. Elidje said the girl had an infection related to sexual assault and had been in acute shock, untreated, for days.

Her family said the girl had been raped by Russian fighters who attacked their village and beheaded the girl’s uncle. The family and other refugees either spoke on condition of anonymity or gave only their first name for fear of retaliation.

“We were all scared because we thought after the girl, they would exterminate us all. I had heart palpitations; my heart was racing” said the young girl’s aunt.

They are among more than 3,300 people who have fled violence in northern Mali and crossed into Mauritania in the past month as al-Qaida-linked JNIM fighters impose a fuel blockade across Mali.

Legal experts say that Africa Corp’s existence as a Russian military unit makes Russian authorities directly responsible for the fighters' actions.

Malian authorities have never publicly acknowledged the presence of Wagner or Africa Corps. But Russian state media in recent weeks have published reports from Mali, praising Africa Corps for defending the country from “terrorists.” The Russian ministry of defense did not respond to questions regarding the allegations presented by the AP.

The AP also learned of four other alleged cases of sexual violence, including what women described as attempted rape by Africa Corps fighters.

The U.N. says sexual assaults have occurred over more than a decade of conflict in Mali, with all sides to blame. The sexual violence remains under-reported because of fear of reprisals, limited access to care and deeply embedded shame around sexual assault, according to the U.N. and aid workers.

“We are convinced that there are many cases like this,” said the clinic manager, Elidje, adding that very few patients seek treatment because it’s a taboo subject.

“They only come when things have already become complicated, like the case we saw today” with the 14-year-old.

Both Wagner and Mali's army have been accused by the U.N. of war crimes against civilians, including massacres and rapes, as violence in the conflict has reached record levels. Thousands of people have been killed across the region and millions displaced.

“There is a lot of people raped, attacked, killed. Families are separated, there is no doubt about that,” said Sukru Cansizoglu, the representative in Mauritania for the U.N. refugee agency. But “it is sometimes difficult to really pinpoint who are the perpetrators.”

Two refugees showed videos of villages they said were burned by Africa Corps. Two others said they found bodies of loved ones with liver and kidneys missing.

“It’s a scorched-earth policy,” said one Malian village chief who fled to Mauritania last month for the second time. “These people don't even talk to us. As soon as they encounter someone, they kill them.”

Experts say it's impossible to know how many people are being killed and assaulted in Mali, especially in remote areas, while journalists and aid workers have increasingly limited access to the country.

AP Video shot by Caitlin Kelly