KANO - Suspected Islamists threw explosives and fired at a Nigerian military checkpoint on Wednesday, igniting a gunbattle in the city of Kano where attacks in January killed 185, military sources and a witness said. “Our checkpoint ...came under attack this morning by gunmen believed to be members of Boko Haram,” a military source told AFP. “The soldiers repelled the attack and arrested four suspects” in the wake of the dawn assault that shook the northern city still trying to recover from the January 20 deadly bomb-and-gun assault.