Former negotiator believes Boko Haram targeted girls to force concessions . France said Thursday that it would send a `` specialized team '' to help . Nigerian security chiefs call on those with information about the girls to come forward . Comment: France joins United States , Britain , China in search for girls abducted by group .
Former negotiator believes Boko Haram targeted girls to force concessions . Nigerian security chiefs call on those with information about the girls to come forward . Comment: France joins United States , Britain , China in search for girls abducted by group .