Ten prisoners have been found guilty of raping dozens of female inmates during a violent riot at an overcrowded jail in the Democratic Republic of Congo.

Thirty-seven women and a teenage girl testified that they were repeatedly raped during a three-day riot at Kasapa Central Prison near Lubumbashi in 2020.

Some female detainees became pregnant and contracted sexually transmitted infections, including HIV.

The 10 men were fined and ordered to serve 15 additional years in jail.

Although some of the inmates were too frightened to give evidence, dozens testified before a military prosecutor that they had been raped during the riot.

Melanie Mumba, a lawyer for the victims, told AFP news agency: "We are satisfied with the verdict, after a long struggle to gain justice".

The run-down prison facility was taken over by a group of male inmates for several days in September 2020.

They set the women's section of the prison on fire with female detainees - including a 16-year-old girl - forced to sleep in a prison yard where they were subjected to sexual assaults.

Some 20 inmates and a prison guard were reportedly killed during the violence before security forces regained control.

The mass rapes were highlighted in reports by Human Rights Watch (HRW), who urged authorities to investigate the assaults and offer adequate care to those impacted.

The campaign group said the prison, built to house 800 inmates, had almost 2,000 people in detention during the incident. It said poor hygiene, sanitation and healthcare were all reported at the facility, with repeated warnings a riot would break out reportedly ignored by senior officials.

Thomas Fessy, senior DR Congo researcher at HRW, told the BBC that the prosecution of 10 inmates "should only be seen as a first step".

"Of the 56 female detainees in the prison at the time of the riot, 37 women and a teenage girl testified to Lubumbashi's public prosecutor that male inmates had raped them and every perpetrator should be held accountable for these acts," he said in an emailed statement.

Mr Fessy also said the Congolese state had "failed to protect and provide safety" for inmates during the incident.

Noella Bashizi, a defence lawyer for the accused, told the AFP news agency she would consult her clients about whether to appeal against the sentences given on Wednesday.

HRW reported in 2021 that at least seven detainees, including a 16-year-old girl, became pregnant amid the unrest.

AFP, citing lawyers for the victims, put the number of pregnancies at 16.