ABUJA, Nigeria—Gunmen have killed nearly 70 members of a local defense group in Nigeria’s northwest region in attacks since Sunday and the violence is continuing, members of the force and residents told The Associated Press. The attackers ambushed members of the local defense group in the Zuru area of Kebbi state as they were responding to calls for help in some remote villages, John Mani, a leader of the civilian defense force in Zuru, said Tuesday. At least 67 people have been confirmed dead from attacks by the gunmen, said Mani, who added that the death toll is expected to rise as the attackers “are still operating.” “They just lay ambush on my people. They came and were doing their operations and my people went to see if they can help because the authorities are not doing anything,” he told AP. Though Kebbi police spokesman Nafiu Abubakar confirmed the incident, …