Hajar Adamu spent three weeks as a prisoner of Boko Haram, the Islamist militant group in Nigeria. She is one of dozens of survivors who posed for photographer Andy Spyra.
Saratu Zakariya spent seven months in captivity. A Christian, she was forced to learn the Quran and threatened with death if she didn't obey and marry a Boko Haram fighter. When she refused, she was severely whipped. She eventually escaped during an evening prayer when the fighters went to a mosque. Her children were kept in a different camp, and she did not know their whereabouts.
Hajaru Buba's child was the result of a Boko Haram rape, Spyra said.
Ladi Idrisa was a prisoner for four months. She is a Muslim, as are many of the women in these photos.
Amina Adamu spent four months as a prisoner until she escaped.
Halima Saleh was a prisoner for four months. "This is how I could best convey their characters and their personalities," Spyra said of the portraits. "They were radiating, they were strong personalities. I was impressed by their presence after all they had been through, so strong and confident. It really was powerful."
Laraba Bitrus was working in a shop when Boko Haram overran the town of Gwoza in northeastern Nigeria. She was held captive for 11 days and had to witness her uncle's head being sawed off by Boko Haram fighters.
Zainab Musa poses for a portrait. Spyra said some of his subjects "escaped during bombardment of Boko Haram-held villages. Some of them scaled fences. Some of them had smart ideas about saying they were going to the market, and they just ran off."
Tani Bitrus was detained alongside 50 other women in Gwoza. Her husband was executed by Boko Haram.
Jara Ahmadu was held by Boko Haram for a week. Spyra and colleague Wolfgang Bauer helped raise money for the women and set them up with bank accounts.
Hauwa Isa was a prisoner for eight months. "We heard stories of dead bodies and mass graves, the others in the forest of people who didn't make it," Spyra said. "There were snakes and scorpions, rivers that you had to cross where thousands of women have died in their attempt to flee. These women are really strong and really tough, and how they did it, I don't know."
Mary John Ibrahim was working in a government hospital when Boko Haram overran the area and burned down the hospital.
With a piece of black cloth, a few rags and a little chair, Spyra created his makeshift studio at a church compound. Salamatu Ibrahim, pictured here, spent five months in captivity.
Fadi Muhammadu spent a month and a half in captivity.
Fabi Buba was held for a month. "I had this wish to come back and help them in a real concrete way, to come back with something physical in my hands to give back to them," Spyra said.