A French family has been kidnapped by gunmen in Cameroon, near the Nigerian border, French president François Hollande says. The attackers were a "known terrorist group based in Nigeria," he adds, and probably took the family there. The seven victims included children. The attack comes just days after seven foreigners were kidnapped in Nigeria's Bauchi state; the Nigerian militant group Ansaru took credit, the BBC notes. Another militant group, Boko Haram, has been behind a number of attacks in the country.