KANO, Nigeria — In this northern city, the second most populous in Nigeria, protesters have been converging at the city center and making their way to Government House, seat of the state governor. While protests are not unusual in Nigeria, it’s less common in the predominantly Muslim north outside of university campuses. Now this level of the protests and sheer numbers of protesters in the big cities of northern Nigeria have caught onlookers, participants, and authorities off guard. Even though the “End bad governance” protests have been nationwide, the 13 people killed as of Saturday Aug. 3 were in three northern states, according to Amnesty International. Curfews have been imposed in Kano and other northern states including Jigawa, Katsina and Borno.