LAGOS, Nigeria (AP) -- Some of the nearly 300 girls and women freed by Nigeria's military from the forest stronghold of Boko Haram were so transformed by their captivity that they opened fire on their rescuers, and experts said Wednesday they would need intensive psychological treatment.
The military was flying in medical and intelligence teams to evaluate the former captives, many of whom were severely traumatized, said army spokesman Col. Sani Usman.
He said earlier that none of the schoolgirls kidnapped from the northeastern town of Chibok a year ago appeared to be among the 200 girls and 93 women rescued Tuesday. But on Wednesday he said further screening was needed before their identities could be determined.
"The processing is continuing, it involves a lot of things because most of them are traumatized and you have got to put them in a psychological frame of mind to extract information from them," Usman said.
A counselor who has treated other women freed from Boko Haram captivity said some had become indoctrinated into believing the group's Islamic extremist ideology, while others had established strong emotional attachments to militants they had been forced to marry.
Some of the about 90 women and girls freed by the army four months ago in Yobe state, for example, had upset their community on their return by maintaining that the militants were good people who had treated them well, said the counselor, who spoke to The Associated Press on condition of anonymity because he has been targeted by the militants in the past.
"The trauma suffered by the (abducted) women and girls is truly horrific," said Amnesty International's Africa director for research and advocacy, Netsanet Belay. "Some have been repeatedly raped, sold into sexual slavery or indoctrinated and even forced to fight for Boko Haram."
That is what appeared to have happened this week when the Nigerian military said troops rescued the women and girls while destroying four Boko Haram camps in the Sambisa Forest.
Boko Haram used some of the women as armed human shields, a first line of defense who opened fire as the troops approached, according to an intelligence officer and a soldier who were in Sambisa during the rescue. The soldiers managed to subdue the women and round them up, said the men, who spoke on condition of anonymity because they were not authorized to discuss the sensitive issue with the media.
No one knows how many captives are in the hands of the Islamic extremists, who have carried out a campaign of killings and kidnappings that has seen thousands of girls, women and young men seized to be used as sex slaves and fighters. Amnesty International said earlier this month that at least 2,000 women and girls have been taken by Boko Haram since the start of 2014.
Among them are the nearly 300 girls abducted from their school in Chibok on April 14, 2014. Dozens escaped as they were taken in trucks into the Sambisa forest, but 219 remain missing.
The plight of the schoolgirls, who have become known as "the Chibok girls," aroused international outrage and a campaign for their release under the hashtag (hash)BringBackOurGirls. Their kidnapping brought Boko Haram, whose nickname means "Western education is forbidden" in the local Hausa language, to the world's attention, with even U.S. first lady Michelle Obama becoming involved as she tweeted a photograph of herself holding the campaign sign.
Nigerian military and counter-insurgency spokesmen have said they have information indicating at least some of the Chibok girls still are being held in the Sambisa Forest.
Usman said operations were continuing Wednesday, as the military evacuated the women and girls freed a day earlier and took them to an undisclosed location.
"Sambisa Forest is a large expanse of land, so what we were able to get is four out of several terrorist camps in the forest," he said of the national game reserve that sprawls over 60,000 square kilometers (23,170 square miles).
Some kidnapping victims who have escaped from Boko Haram have been detained for weeks for security screenings, and Amnesty International called on authorities "to ensure that the trauma of those `rescued' is not exacerbated by lengthy security screening in detention."
"Amnesty International is calling on the authorities to ensure that their physical and psychological well-being is paramount," the group said in a statement.
Former British Prime Minister Gordon Brown, now the U.N. special envoy for global education, welcomed the rescue of the girls and women but called Wednesday for the immediate release of all abducted girls.
"It is time to end the nightmare. For a year, families have not known whether their daughters are dead or alive, married off, sold off or violated as a result of their captivity," Brown said. "We want all girls released."
Nigeria's military largely stood by last year as Boko Haram took over dozens of towns and declared a large swath of northeastern Borno state an Islamic caliphate.
That changed when a multinational offensive led by Chad began at the end of January. Now, Nigeria's military says it has driven the Islamic extremists out of all towns with help from troops from Chad and Niger, while Cameroonian soldiers have been guarding their borders to prevent the militants from escaping.
A month ago the Nigerian military began pounding the Sambisa Forest in air raids, an assault they said earlier they had been avoiding for fear of killing kidnapped women and girls, or inciting their captors to kill them.
Boko Haram continues to attack isolated communities. The government of neighboring Niger said a Boko Haram attack on Karamga island in Lake Chad over the weekend killed 156 militants, 46 soldiers and 28 civilians.