Clashes between rival ethnic groups have killed at least 39 people in eastern Nigeria's Taraba state since they erupted on Friday, police said.
Members of the Jukun were marching through the small commercial town of Wukari to a funeral when an argument broke out with local Hausa and Fulani youths, which quickly degenerated into pitched battles with guns and machetes.
Attackers set fire to around 40 houses, police said.
"At the end of the clash, 39 people were counted killed," said the police spokesman for Taraba state, Joseph Kwaji.
He said that 32 people were injured and 40 were arrested.
Taraba state is part of a volatile "Middle Belt" where Nigeria's largely Christian south and mostly Muslim north meet. Violence often flares in the Middle Belt over land disputes between semi-nomadic, cattle-keeping communities such as the Fulani and settled farming peoples like the Jukun.
Fulani settlers tend to be Muslim and other ethnic groups who see themselves as indigenous to the Middle Belt, including the Jukun, are mostly Christian, which sometimes gives the clashes a religious dimension.
Communal violence has also flared this year in Plateau state, which borders Taraba.
Last month, the U.S. Commission on International Religious Freedom, a bipartisan U.S. government agency, said more than 100 people had been killed in clashes there since March, and it urged the government to do more to tackle what it called religious violence.