At least 20 people died when extremists threw hand grenades at a crowd of mourners during a funeral service in the Central African Republic capital Bangui overnight, the government said on Friday.
The attack occurred about 11 p.m. Thursday night local time in Fatima, a Muslim neighborhood of the capital, Bangui.
Local residents blame the attack on former fighters from the Seleka militia.
The country has been hit by civil conflict since Seleka rebels ousted the president in March 2013.
The head of the African peacekeeping force in the C.A.R., General Jean-Marie Michel Mokoko, said this week that his forces will now treat the anti-balaka as "enemies."
The anti-balaka — whose name means "machete proof" or invincible — formed last year in response to a wave of killing and looting by mostly Muslim Seleka rebels.
However, Mokoko told a Bangui radio station that the militias will not be treated as self-defense groups.
There are about 6,000 African Union troops in the C.A.R., working alongside 2,000 French troops in efforts to protect civilians and disarm militias.