The United States is calling on Nigeria's government to ensure the perpetrators of Sunday's massacre near the city of Jos are brought to justice.
Officials supervised a mass burial of bodies late Monday in Dogo Nahawa, one of three mainly Christian villages attacked by Muslim herders.
A Plateau state official, Solomon Zang, said about 380 bodies were buried. However, the final death toll from the violence is not yet clear. Other state officials have placed the toll as high as 500.
In a statement, U.S. Secretary of State Hillary Clinton says Nigerian authorities should bring the perpetrators to justice while respecting human rights as order is restored.
Police say they have arrested about 95 people in connection with the violence.
Human Rights Watch has asked Nigeria's Acting President Goodluck Jonathan to ensure that police and soldiers prevent any reprisal attacks.
Mr. Jonathan on Monday fired his national security adviser, Sarki Mukhtar, and replaced him with Aliyu Gusau. Gusau served as security chief for former President Olusegun Obasanjo.
Witnesses say ethnic Fulani herdsmen attacked the mainly Christian villages around 3 a.m. local time Sunday, setting homes on fire and hacking people with knives and machetes.
Some residents are asking why the villages were left unprotected. The area has been under a dusk-to-dawn curfew since January, when another outburst of Muslim-Christian violence in Jos killed about 325 people.
Jos has a history of such sectarian violence. Previous clashes in the city killed about 200 people in 2008, 700 people in 2004 and 1,000 people in 2001.
The city sits on the dividing line between Nigeria's mainly Muslim north and predominantly Christian south.
In a statement Monday, U.N. Secretary-General Ban Ki-moon called the killings near Jos "appalling." He urged Nigeria's political and religious leaders to work together to address the underlying causes of the violence in the area.
Some information for this report was provided by AFP and Reuters.