Officials and witnesses in the Central African Republic say suspected Muslim rebels have killed at least 34 people over the past week in a series of raids on northern villages.
Witnesses said Saturday that they believe the attackers were ex-Seleka fighters.
They say some of the attackers threatened to raid more villages before a United Nations peacekeeping force is deployed to the C.A.R. in mid-September.
The French News Agency says some villagers were shot at point-blank range while others were hanged, tortured or beaten to death.
The C.A.R.'s ethnic and religious unrest began last year, when the mainly Muslim Seleka rebel coalition toppled the government. In response to the ensuing violence, largely Christian communities formed "anti-balaka" vigilante forces, that have carried out revenge attacks on Muslims.
Thousands of people have died in the unrest and more than one million civilians have been displaced.
French and African Union forces deployed to the C.A.R. have had limited success in quelling the violence.
Earlier this month, interim President Catherine Samba-Panza appointed a Muslim prime minister, who will lead a transitional government that is seeking to implement a cease-fire signed last month.
Samba, who is Christian, appointed former special adviser Mahamat Kamoun to the post.
Seleka and anti-balaka forces signed the tentative peace agreement in the Congo, in July.