After 913 days of captivity, the Chibok schoolgirls were dazed and tearful as they huddled together in a government office. Their arms were thin, their faces were gaunt, but they were free at last.
These early images of the 21 freed schoolgirls – the first of the Chibok students to be released in a negotiated deal with Boko Haram – were a sight that the world had been anxiously awaiting for more than two years.
Boko Haram, a radical Islamist militia that has killed thousands of people in Nigeria and neighbouring countries, shocked the world by abducting 276 teenaged girls from a Chibok school in northeastern Nigeria on April 14, 2014. It was an act that provoked global outrage and sparked international campaigns for their release.
Nigeria's government announced that the 21 schoolgirls were released in the pre-dawn hours on Thursday, in a deal brokered by the Swiss government and the International Committee of the Red Cross. Reports said the government had swapped the students in exchange for the release of four high-ranking Boko Haram officials in Nigerian custody, although the government denied this.
The freed students were taken in Red Cross vehicles to a remote town near the Cameroon border, then flown to the Nigerian capital, Abuja, where they escorted into a meeting with Vice-President Yemi Osinbajo on Thursday night.
A team of doctors, psychologists and trauma experts was assembled in Abuja to examine the schoolgirls. "You can't immediately be taken out of here because we need to be sure that you are in very good health," Mr. Osinbajo told them. He promised that their parents would be allowed to meet them.
Photos and video clips released by the government showed the young women in rows of chairs in a meeting room, apparently healthy, although sombre and thin.
No longer dressed in the Islamic garb that Boko Haram had forced them to wear, they wore colourful new patterned dresses and headwraps. One woman was holding a 20-month-old boy, which the government said was her son.
When the news of the abduction first emerged in 2014, many Nigerian officials seemed indifferent to the abduction, suggesting it was a hoax. Later the Nigerian military pledged to rescue the schoolgirls, but their attempts were unsuccessful. A few dozen managed to escape on their own. After the release on Thursday, 197 schoolgirls are believed to be still held by Boko Haram, though some have reportedly died.
A local news agency in Nigeria, quoting a Boko Haram commander and other sources, reported that the 21 women were released in a "prisoner swap" for four senior Boko Haram militants in Nigerian custody. Similar reports have emerged from other agencies, quoting Nigerian government sources. One local report said the government had paid a ransom.
But the government is denying the prisoner swap. The schoolgirls were freed as a result of "painstaking negotiations," a government statement said.
"We see this as a credible first step in the eventual release of all the Chibok girls in captivity," the statement said. "It is also a major step in confidence-building between us as a government and the Boko Haram leadership on the issue of the Chibok girls."
Nigerian President Muhammadu Buhari tweeted his reaction to the news. "I welcome the release of 21 of our Chibok girls, following successful negotiations," he said.
The released schoolgirls are "very tired" and are staying in government custody, according to Garba Shehu, a spokesman for Mr. Buhari.
The International Red Cross, which is bound by rules of confidentiality, gave only a terse confirmation of its role in the release. "Today we transferred 21 of the Chibok girls and handed them to the Nigeria government authorities, acting as a neutral intermediary," it said.
The schoolgirls were transported in Red Cross vehicles to the town of Kumshe, in northeastern Nigeria near the Cameroon border, according to the AFP news agency.
At the same time, a Nigerian military helicopter brought the four senior Boko Haram radicals to a military base at Banki, about 15 kilometres from Kumshe, the news agency said. Then the Red Cross vehicles took the four radicals to Kumshe, where the 21 girls were released and brought back to the military base.
They were then flown to Kaduna, a city in northern Nigeria, and then to Abuja.
A similar account was provided by Sahara Reporters, a Nigerian news agency.
Negotiations will continue for the release of the remaining Chibok schoolgirls who are held by Boko Haram, according to Mr. Shehu, the presidential spokesman. He also said Mr. Buhari wants the country to remember that 30,000 Nigerians have been killed in the Boko Haram conflict.
There was an emotional reaction from the Bring Back Our Girls movement, which has campaigned daily for the release of the schoolgirls.
"I can only weep, right now," said Oby Ezekwesili, a founder of the Bring Back Our Girls group. "You know that kind of cry that is a mix of multiple emotions," she tweeted. "Lord. Some of our girls ARE BACK!!!"
She said the 21 released schoolgirls should be used as a "point of contact" to help locate and rescue the ones who remain in captivity.
In a separate statement, the Bring Back Our Girls group said the release of the abducted students was a "wonderful development" and "extremely joyous news."
In the past, the group has often questioned whether the Nigerian government was doing enough to find and rescue them.
One of the schoolgirls, Amina Ali Nkeki, escaped on her own in May. She was brought to a highly publicized meeting with Mr. Buhari and then kept in government custody, where she is reported to be receiving medical care and counselling.