Over the past week, the Nigerian military claims to have freed more than 700 people from the clutches of Islamist extremist group Boko Haram. A new government offensive against the jihadists' redoubts in the vast and remote Sambisa forest led to the rescue of many captives, including hundreds of women and children who had been seized when Boko Haram overran their villages.

The testimony some shared with reporters is chilling.

When Nigerian soldiers approached a group of trapped women, many apparently cried out for help. Retreating Boko Haram fighters, it appears, chose to attack those who didn't flee with them.

"Boko Haram, who were guarding us, started stoning us so we would follow them to another hideout, but we refused because we were sure the soldiers would rescue us," Asama Umaru, 24, told Reuters. She was part of a group of nearly 300 people, mostly women and children, who made it to a government camp Saturday.

They described the horrors and neglect they endured at the hands of Boko Haram. Some died from disease and malnutrition. "Every day, we witnessed the death of one of us and waited for our turn," Umaru said.

Cecilia Abel, another woman who spoke to Reuters, said she ate almost nothing during two weeks of captivity. "We were fed only ground dry maize in the afternoons. It was not good for human consumption," she said.

One reporter visiting the huddled groups of refugees said she saw children so weak that they were "just little skeletal bodies with flaps of skin that make them look like old people."

Other survivors recounted what befell their husbands and older sons, many slaughtered before their eyes by the militants. Some surviving women were forcibly "married" to Boko Haram militants. A few were spared that outcome, including Lami Musa, 27, who was pregnant.

"When they realized I was pregnant, they said I was impregnated by an infidel [her husband] and they killed him," Musa told the BBC. She delivered her baby the night before soldiers arrived to rescue her.

As Washington Post foreign correspondent Kevin Sieff reports, the mass abduction of villagers has been a signature of Boko Haram's bloody insurgency, which has claimed thousands of lives since it flared in Nigeria in 2009. A recent UNICEF study focused on the suffering of hundreds of thousands of children who have been forced to flee their homes by the ravages of Boko Haram.

"Children have become deliberate targets, often subjected to extreme violence — from sexual abuse and forced marriage to kidnappings and brutal killings," the report added.

The Nigerian military has been criticized for its handling of the insurgency. Hundreds of schoolgirls who were seized by the miltants from the town of Chibok remain missing more than a year after their abduction.

In the recent operations, some of the women in Boko Haram captivity fell victim to the Nigerian military.

"When the military stormed the camp where we were being held, our captors told us to take cover under trees and shrubs to avoid military shelling," an 18-year-old rescued captive told reporters. "Some women who hid under trees were crushed by military tanks which mowed them down without knowing they were there."