The Central African Republic's government says 60 people have been killed in clashes between fighters loyal to ousted president Francois Bozize and the rebels who now hold power.
A government spokesman says the fighting took place Saturday and Sunday around the northwestern town of Bossangoa, in Bozize's home region.
The United Nations says 80 percent of the town's population, about 30,000 people, have fled into the wilderness or to other areas.
U.N. officials say two aid workers were among those killed in the violence.
The fighting was between the Seleka coalition of rebels who ended Bozize's 10-year-rule in March and rival militia groups.
The head of the U.N. humanitarian office in CAR says the Seleka rebels have been aggressive in trying to identify the rival militias, and has intimidated the population and burnt down villages in the process.
The U.N. refugee agency says the violence has forced more than 62,000 people out of the country since September.
The Seleka coalition of rebels is trying to push through a political transition process with elections in the country in the next 18 months.
The Central African Republic has endured a long series of coups and rebellions since gaining independence from France in 1960.