The recently released Chibok girls reunited with their families amidst laughter and tears in the Nigerian capital of Abuja. Still, 113 girls are being held by Boko Haram militants. Anadolu Agency/Getty Images hide caption

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Anadolu Agency/Getty Images

Helmeted Chadian and other African police commandos, armed with dummy rifles hunt down terrorist suspects who've taken hostages in the building, during a US military led Flintlock 2017 law enforcement exercise in Ndjamena Chad, 15 March 2017. Ofeibea Quist-Arcton/NPR hide caption

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Ofeibea Quist-Arcton/NPR

People gather at the site of a suicide bomb attack at a market in June 2015 in Maiduguri, Nigeria, where two girls blew themselves up near a crowded mosque. Jossy Ola/AP hide caption

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Jossy Ola/AP

This camp near Maiduguri, Borno State, in northeastern Nigeria houses more than 16,000 displaced persons. Stefan Heunis /AFP/Getty Images hide caption

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Stefan Heunis /AFP/Getty Images

Protesters outside the Nigerian High Commission in London hold up placards demanding help from the Nigerian government to find missing girls a year after their kidnapping by Islamic extremists in April 2014. Alastair Grant/AP hide caption

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Alastair Grant/AP

Displaced women at the Muna informal settlement outside Maiduguri. They're among more than 2 million people driven from their homes by Boko Haram attacks during northeastern Nigeria's 7-year insurgency. Ofeibea Quist Arcton/NPR hide caption

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Ofeibea Quist Arcton/NPR