Libyan authorities released on Wednesday 28 Eritreans and seven Nigerians who were captured and enslaved by Islamic State in Sirte and had been held in detention since the jihadist group lost the city in December.

The group, all but two of whom are women and children, escaped from Sirte, a former Islamic State stronghold in central Libya, while forces from the nearby city of Misrata battled to oust the militants late last year.

Some of the women were on their way to Europe when Islamic State fighters kidnapped and held them as sex slaves.

After they escaped from Sirte, they were investigated for possible ties to the group and held for several months in a Misrata prison.

Reuters has documented how Islamic State used enslaved refugee women to reward its fighters in Libya. In stories published last year, the women recounted how the group forced them to convert to Islam and sold them as sex slaves.

In November, a Reuters reporter visited some of the captives at a military post in Misrata. Their new captors, the women said then, starved and humiliated them. At least one woman, a 16-year-old, was pregnant and in need of urgent care.

Read the whole story from Reuters.