ABUJA, Nigeria (AP) — Gunmen killed at least 13 people in northern Nigeria, the police said Wednesday, the latest in a surge of attacks that has plagued the West African country. The attackers, “armed with dangerous weapons, began shooting sporadically” on Tuesday in Doma village in the Faskari area of northwestern Katsina state, police spokesman Abubakar Sadiq Aliyu said in a statement. Investigations were underway to determine the circumstances and identify those responsible, he added.