Nigeria's defence minister has reportedly warned that it could take years to find all the Chibok girls who were abducted by the Islamist insurgent group Boko Haram about three years ago.
According to Voice of America, General Manir Dan Ali said that the west African country's defence forces were searching the insurgent group's hideout at the Sambisa Forest, a vast area covering at least three states.
However, he cautioned that it could take years to find the remaining Chibok girls. He made a comparison to the hunt by the United States for the late al-Qaeda leader, Osama bin Laden.
"It took the US up to seven, eight, up to 10 years before they could get to Bin Laden," he said.
"We are continuing our campaigning in the Sambisa Forest in all its nooks and corners," Ali was quoted as saying.
But, according to a member of an influential interfaith group that tries to ensure peace between Nigerian Muslims and Christians, Sheikh Nuru Khalid, if the Chibok girls were not found, that would mean a victory for the insurgent group.
This comes just days after Nigerians marked three years since the mass abduction of more than 200 schoolgirls in Chibok.
The kidnapping of those schoolgirls from a northern Nigerian town made international headlines and prompted global figures, including former US first lady Michelle Obama and a list of celebrities, to support the #BringBackOurGirls campaign.
None of the girls were seen again until May last year when one of the students, Amina Ali, was found in a forest with a baby, along with and a man claiming to be her husband.
Her discovery prompted hopes that the girls were alive, and Nigerian President Muhammadu Buhari pledged to ensure the release of the remaining girls.
Following Amina's recovery, a group of 21 girls was released after Switzerland and the International Red Cross brokered a deal with Boko Haram.
Those girls were briefly allowed to return to their homes to spend Christmas with relatives.
But, after their brief freedom on Christmas Day, the girls were sent back to a secret location in the capital Abuja for debriefing by the Nigerian government.