Islamist terror group abducted 97 people last week , security forces said . Boko Haram has been waging a five-year armed insurgency to create an Islamic state in northern Nigeria . Chadian security forces ambushed a convoy along Lake Chad . 85 of the people in the convoy were rescued , authorities said .
Islamist terror group abducted 97 people last week , security forces said . Chadian security forces ambushed a convoy along Lake Chad . 85 of the people in the convoy were rescued , authorities said .