Nigerian authorities said a female suicide bomber killed at least six people and wounded six others on a college campus in Kano City.
Officials said Wednesday’s attack at Kano Polytechnic College marked the fourth such attack in the city by a woman in less than a week.
The latest attacker blew herself up while a group of students stood around a bulletin board.
There was no immediate claim of responsibility, but several attacks in the area in the last week have been blamed on the Islamist group Boko Haram.
Experts said the use of female attackers in Kano would be a new tactic for the group, which kidnapped 200 Nigerian school girls earlier this year.
Meanwhile, Nigerian police arrested a 10-year-old girl wearing explosives strapped to her chest in the neighboring state of Katsina.