(A woman holds a sign during a protest demanding the release of abducted secondary school girls from the remote village of Chibok, in Lagos May 5, 2014. The Islamist militant group Boko Haram claimed responsibility on Monday for the abduction of more than 200 schoolgirls during a raid in the village of Chibok in northeast Nigeria last month, the French news agency AFP reported, citing a video it had obtained. Boko Haram on April 14 stormed an all-girl secondary school in Chibok, in Borno state, then packed the teenagers, who had been taking exams, onto trucks and disappeared into a remote area along the border with Cameroon. REUTERS/Akintunde Akinleye)

(A woman holds a sign during a protest demanding the release of abducted secondary school girls from the remote village of Chibok, in Lagos May 5, 2014. REUTERS/Akintunde Akinleye)