Nigeria's President says disagreement in Boko Haram delaying Chibok girls release

Some of the Chibok girls freed in swap deal with Boko Haram last year.

Nigeria, Lagos (CNN)Negotiation talks between the Nigerian government and Boko Haram militants on the release of the remaining Chibok girls have been set back, President Muhammadu Buhari said.

A disagreement between members of the terror group is responsible for the breakdown in negotiations, Buhari said in a statement Friday.
"Unfortunately, the negotiations between the government and Boko Haram have suffered some unexpected setbacks, owing mainly to a lack of agreement among their abductors." Buhari said.
    This statement comes as Nigeria marks the four-year anniversary of the abductions in which militants seized 276 girls from a boarding school in Chibok town in Borno state, sparking a global outrage.
    Some of the girls were freed last year following negotiation talks between the Nigerian government and Boko Haram.
    However, more than 100 Chibok girls remain in captivity four years later.
    Bring Back Our Girls group which has long campaigned for the safe return of the girls, marked the anniversary on Saturday with a march in Lagos and a lecture given by Tunde Bakare, a prominent cleric in Nigeria's capital Abuja.
    President Buhari said though it has taken so long to secure their release, government was doing its best to free the remaining Chibok girls from their abductors.
    He said the return of over 100 schoolgirls kidnapped by Boko Har