Nigeria's acting president replaced his national security adviser Tuesday, two days after mobs massacred hundreds in villages in central Nigeria.
It was not clear why President Goodluck Jonathan made the replacement, or whether it was related to the weekend violence in villages south of Jos, in Plateau State. Lt. Gen. Aliyu Gusau replaced Maj. Gen. Sarki Mukhtar in the post.
At least 200 Christian villagers died in the attacks early Sunday, when groups of men with guns, machetes, and knives attacked people in three villages, Human Rights Watch said Monday.
Human Rights Watch cited witnesses as saying the attackers were Muslim men and that they targeted Christians, mostly from the Berom ethnic group. The victims were in the villages of Dogo Nahawa, Zot, and Ratsat, about 10 kilometers (6 miles) south of Jos, the state capital.
The U.S. diplomatic mission to Nigeria expressed its "deep regret" at the violence in the area, and called on the Nigerian government to make sure the attackers are brought to justice.
- CNN's Christian Purefoy in Jos, Nigeria, contributed to this report.