About 2,000 people have sought refuge in a Catholic mission after heavy fighting broke out in the volatile north-west, aid workers said.
The latest exodus came as a top Catholic church official in the region warned that the violence has taken on a “dangerous Muslim-Christian sectarian character that the country has never experienced”.
There was no immediate casualty toll available from the fighting, Petula Malo of the Caritas charity said.
The town of Bouca, north of the capital, Bangui, is normally home to fewer than 1,000 residents. Heavy fighting erupted on Tuesday between the Muslim Seleka rebels and members of Christian militias that have arisen as self-defence groups amid the violence.