(CNN) -- A day after the world had its first apparent glimpse of the kidnapped Nigerian schoolgirls in a month, the question remains the same: what can be done to free them?
Shehu Sani, a former negotiator between Boko Haram and the government, has called for the Nigerian authorities to negotiate with the girls' Islamist captors -- and says they may have to embrace the unpalatable option of a prisoner swap.
"There are two ways to which you can get these girls free," Sani told CNN's "Connect the World" show.
"The first is to use force and the second is through dialogue. The use of force is not an option for now in the sense that nobody knows where these girls were kept.
(http://i.cdn.turner.com/cnn/.e/img/3.0/mosaic/bttn_close.gif) (http://i2.cdn.turner.com/cnn/dam/assets/140511165235-chibok-nigeria-story-body.jpg)Nigerians take security into own hands
(http://i.cdn.turner.com/cnn/.e/img/3.0/mosaic/bttn_close.gif) (http://i2.cdn.turner.com/cnn/dam/assets/140512115559-pkg-nima-elbagir-abducted-girls-00014109-story-body.jpg)Witnesses to Terror
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People march in Lagos, Nigeria, on Monday, May 12, to demand the release of schoolgirls kidnapped from Chibok last month. The abduction of nearly 300 female students who remain captives of the Islamist militant group Boko Haram has attracted mounting national and international outrage.
Catholic faithful take Holy Communion and pray for the safety of the kidnapped schoolgirls in a morning Mass in their honor in Abuja, Nigeria's capital, on Sunday, May 11.
Catholic faithful attend a morning Mass in honor of the kidnapped Chibok schoolgirls, in Abuja, Nigeria, on May 11.
Catholics nuns pray during a morning Mass in honor of the kidnapped Chibok schoolgirls, in Abuja, Nigeria, on May 11.
A woman attends a demonstration Tuesday, May 6, that called for the Nigerian government to rescue nearly 300 schoolgirls who were kidnapped last month in Chibok, Nigeria. The girls were taken by the Islamist militant group Boko Haram.
Abuja Hosea Sambido, a leader in the Chibok community, speaks during a rally in Abuja, Nigeria, on May 6, pressing for the release of the abducted girls.
Brig. Gen. Chris Olukolade, Nigeria's top military spokesman, speaks to people at a demonstration on May 6.
Women march Monday, May 5, in Chibok.
People rally in Lagos, Nigeria, on Thursday, May 1.
Police stand guard during a demonstration in Lagos on May 1.
Protesters take part in a "million woman march" on Wednesday, April 30, in Abuja.
Obiageli Ezekwesili, former Nigerian education minister and vice president of the World Bank's Africa division, leads a march of women in Abuja on April 30.
A woman cries out during a demonstration Tuesday, April 29, in Abuja with other mothers whose daughters have been kidnapped.
A man weeps as he joins parents of the kidnapped girls during a meeting with the Borno state governor in Chibok on Tuesday, April 22.
Mothers weep during a meeting with the Borno state governor on April 22 in Chibok.
Four female students who were abducted by gunmen and reunited with their families walk in Chibok on Monday, April 21.
Borno state governor Kashim Shettima, center, visits the Chibok school on April 21.
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
Nigerians protest over kidnapped schoolgirls
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(http://i2.cdn.turner.com/cnn/dam/assets/140512095958-01-nigeria-0512-horizontal-gallery.jpg) Photos: Nigerians protest over kidnapped girls "And even if you know, these girls have been embedded in with the insurgents who are heavily armed. And any attempt to rescue them will be putting their lives in further danger."
The video, released by French news agency Agence France-Presse and seen by CNN, purports to show about 100 of the 276 girls kidnapped by Boko Haram (http://www.theinfostride.com/forum/'http://www.cnn.com/2014/04/17/world/africa/boko-haram-explainer/index.html') fighters on April 14.
In separate shots included in the 27-minute video, a man who identifies himself as Boko Haram leader Abubakar Shekau (http://www.theinfostride.com/forum/'http://www.cnn.com/2014/05/07/world/africa/abubakar-shekau-profile/index.html') says he will release the girls only after imprisoned members of Boko Haram are freed.
Nigerian officials argued Monday that Shekau is dead. Other experts say the notorious terror group leader is still alive.
The director of the National Orientation Agency, a government information ministry, said negotiations could be an option when it comes to rescuing the kidnapped girls.
When asked whether all options were on the table, agency director Mike Omeri said yes.
"The government of Nigeria will continue to explore all options for the release and safe return of our girls back to their respective homes," Omeri told CNN.
Girls' lives 'more important'
Sani, who is a human rights activist in northern Nigeria, believes the authorities have little choice.
(http://i.cdn.turner.com/cnn/.e/img/3.0/mosaic/bttn_close.gif) (http://i2.cdn.turner.com/cnn/dam/assets/140512162026-nigeria-map-2-story-top.jpeg) Map: Nima Elbagir's route to Chibok
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(http://i2.cdn.turner.com/cnn/dam/assets/140512162026-nigeria-map-2-story-top.jpeg)Map: Nima Elbagir's route to Chibok
"I believe that the lives of these girls is more important to us than the insurgents that have been in detention. And we have nothing to lose if we send the -- insurgents and we can swap them with these girls back," he said.
The man purporting to be Shekau appeared to open the door to such a resolution.
"By Allah, these girls will not leave our hands until you release our brothers in your prison," he says. "You took our brothers four or five years ago, and now they are in your prisons. You do many things, and now you talk of these girls. We will not let them go until you release our brothers."
But he also says he still plans to sell them into slavery.
Case not clear cut
While negotiations may be an option in some hostage crises, this case may not be so clear cut.
(http://i.cdn.turner.com/cnn/.e/img/3.0/mosaic/bttn_close.gif) (http://i2.cdn.turner.com/cnn/dam/assets/140512074606-newday-boko-haram-nigerian-girls-convert-00000719-story-body.jpg)New video allegedly shows Nigerian girls
(http://i.cdn.turner.com/cnn/.e/img/3.0/mosaic/bttn_close.gif) (http://i2.cdn.turner.com/cnn/dam/assets/140512074606-newday-boko-haram-nigerian-girls-convert-00000719-story-body.jpg)New video allegedly shows Nigerian girls
(http://i.cdn.turner.com/cnn/.e/img/3.0/mosaic/bttn_close.gif) (http://i2.cdn.turner.com/cnn/dam/assets/140512173726-lead-pkg-elbagir-boko-haram-girl-escaped-00005728-story-body.jpg)Nigerian girl escapes from Boko Haram Rights groups have accused Nigeria of using heavy-handed tactics such as illegal searches, torture and extrajudicial killings to crack down on the militants.
As a result, it has eroded trust between the two sides, prompting Boko Haram leader Abubakar Shekau to say he "will not enter a truce with infidels," U.S. lawmakers said last year.
Boko Haram members who try to negotiate with the government may also get beheaded.
"Reports of beheadings seem to go up when there are talks of negotiation. It is plausible that many of these beheadings, which rose in frequency in early 2012, are purges of moderate members who have complained or attempted to negotiate," U.S. lawmakers said.
Experts comb footage for clues
If authentic, the video released Monday is the first glimpse of the girls since Boko Haram fighters snatched them from a boarding school in the northern Nigerian town of Chibok.
Filmed in a nondescript clearing surrounded by scrub and trees, the girls appear dressed in gray or black veils. Many look nervous or under duress. In one shot, a girl almost whispers a line from the Quran.
In separate shots filmed against a green backdrop, the man who claims to be Shekau says the girls -- who come from a Christian stronghold -- have converted to Islam.
A senior administration official told CNN that U.S. officials have no reason to question its authenticity.
"Our intelligence experts are combing over every detail of the video for clues that might help in the ongoing efforts (to) secure the release of the girls," the official said.
Some observers see the release of the video as a positive sign.
Not only would it prove that at least some girls are alive and unharmed, said retired U.S. Maj. Gen. James "Spider" Marks, a CNN military analyst, it also gives intelligence analysts something with which to work.
Nigerian government officials also took notice. The governor of the state where Chibok is located, Borno, ordered officials to distribute the video to parents to help identify the girls.
While experts analyze the video, the international effort to find the girls is gaining steam.
U.S. and British officials are in the capital of Abuja to help look for the girls, plan rescue missions and advise on ways to quash the terror group.
The United States is providing manned Defense Department aerial surveillance planes over Nigerian territory and sharing commercial satellite images with Nigeria as part of efforts to find the girls, two senior Obama administration officials told CNN's Elise Labott on Monday.
China and France are also helping in the search. Israel plans to send a team of counterterrorism experts to help, Nigerian President Goodluck Jonathan's office said Sunday.
CNN's Faith Karimi and journalist Aminu Abubakar contributed to this report.
Source: CNN.com