Escaped captives say that some of the schoolgirls flog dissidents and slit the throats of captured men.
Amnesty International has said that Nigeria's senior military officers received information of a Boko Haram offensive but failed to take action.
Nigerian activists fight daily to ensure the issue of 219 kidnapped girls is not swept under the carpet.
An extraordinary Ecowas security summit has announced plans for a partnership with Central African states to fight "terrorism" in the region.
Discussions between Nigeria's military chiefs and the president over how to rescue schoolgirls abducted by Boko Haram have reached a stalemate.
US planes are flying over Nigeria in search of kidnapped schoolgirls, while a mother has recognised her daughter on footage released by Boko Haram.
The United Nations is demanding Boko Haram to immediately release the more than 200 girls, who are believed to still be within Nigeria's borders.