Eleven people in a funeral in Bangui, capital of the Central African Republic were killed by a grenade attack, Red Cross said.
Even though 20 people were reported by a government minister to be killed, the BBC reported the number to be lower.
Since Seleka rebels ousted the president in March 2013, the country has been afflicted by a continuing civil conflict. According to BBC News, the former fighters from the Seleka militia was accused by local residents for the gruesome attack.
Public Security Minister Denis Wangao Kizimale told national radio that the attack happened around 23:00 on Thursday (22:00 GMT).
Kizimale told local radio that the attackers were "extremists well-known to the police", according to the AFP news agency.
Apart from the 11 deaths, 14 people were also wounded, Antoine Mbao Bogo, head of CAR's Red Cross, told AFP.
Unidentified men mugged and stole phones from Red Cross volunteers on their way to collect bodies, Bogo said.
"There were no casualties but the BBC's Thomas Fessy said the incident shows how difficult it is for aid workers to operate in CAR at the moment," BBC News reported. "The conflict has taken on an increasingly sectarian nature, with UN human rights chief Navi Pillay warning last week that hatred between Christians and Muslims in CAR had reached a 'terrifying level.'"
Horrific attacks, including acts of cannibalism and children's heads being cut off were also committed. Around a quarter of the country's 4.6 million people have fled their homes.
"After the mainly Muslim rebel Seleka group deposed President Francois Bozize and installed their leader Michel Djotodia as president, it was accused of targeting Christians," BBC News reported. "In January, Djotodia was in turn forced to step down amid criticism he had not done enough to stem sectarian violence."
Since then, thousands of Muslims have started fleeing their homes after being singled out for attack. Cameroon and Chad, neighboring countries, have been fled to for refuge.
