Boko Haram militants stoned an unspecified number of captive women to death in northern Nigeria last week rather than allow them to be rescued by the Nigerian army, survivors said Sunday. Officials said the military liberated approximately 700 captives from Boko Haram, including about 300 women and children.

Faced with approaching Nigerian soldiers, Boko Haram fighters threw stones at women who would not run from the militant group’s camp in the Sambisa forest, witnesses told the BBC. Survivors were unable to say definitively how many women were stoned to death. Other women were killed by stray gunfire and land mines while a Nigerian military vehicle accidentally killed three.

"Boko Haram came and told us they were moving out and said that we should run away with them. But we said no," survivor Lami Musa told the Associated Press. “Then they started stoning us. I held my baby to my stomach and doubled over to protect her.”

Boko Haram summarily executed some male captives and forced other women into marriage, survivors said. Captives were fed just one meal per day and were guarded obsessively by Boko Haram militants. Disease and malnutrition reportedly were rampant under the militant group’s watch.

“They didn’t allow us to move an inch. We were kept in one place. We were under bondage,” another female survivor told Reuters.

The freed captives were taken from Boko Haram’s camp in the Sambisa forest to a refugee site outside Yola in northeastern Nigeria, where they received medical treatment. Officials said none of the liberated women was part of a group of approximately 300 schoolgirls kidnapped by Boko Haram from Chibok in 2014.

“Based on the registration we have carried out so far, none of them is from Chibok,” said Zakari Abubakar, a National Emergency Management Agency official active at the refugee site.

In a separate operation, military personnel captured an unnamed individual suspected of providing supplies to Boko Haram in the northeastern Nigerian city of Baga, a Nigerian defense ministry spokesman said in a statement. The suspect will be interrogated. 

Nigerian officials say Boko Haram attacks have killed and displaced thousands of civilians over the last five years.