DAKAR, Senegal  Armed with guns, machetes, torches, and bows and arrows, Christian and Muslim antagonists in central Nigeria’s religiously volatile city of Jos have been fighting for three days in sporadic clashes that have left dozens dead, witnesses and local news accounts said Tuesday.

It was difficult to ascertain the precise toll in Jos, the scene of frequent religious violence over the past decade. Estimates ranged from 30 to 300 deaths, as the city was still consumed by mayhem Tuesday evening, with security forces descending on Jos in an attempt to contain it.

Gunshots could be heard throughout the city, and smoke from burning buildings was visible everywhere, witnesses said.

“This morning there was smoke, and a lot of shooting by the military personnel,” said Shimaki Gad Peter, director of the League for Human Rights, which is based in Jos, in a telephone interview. The violence began Sunday when Muslim youths attacked a church, according to Mr. Peter, “and they were resisted by church members.”