At least 20 people were killed when extremists threw hand grenades at mourners during a Christian funeral service in the Central African Republic capital of Bangui.
"Around 11pm (Thursday) a group of extremists, well known to the police, threw hand grenades at a crowd that was attending a wake," Public Security Minister Denis Wangao Kizimale told national radio.
In addition to the 20 people who died in the attack, 11 others were wounded and hospitalised, he added.
A pregnant women and several children were among the victims a source close to the families at the funeral service said.
"The government condemns this odious act. Already, an inquiry has been opened to determine the circumstances of this crime. Those responsible will be found and brought to justice," said Kizimale.
Members of the local community held an angry street protest on Friday, blaming the attack on Muslims.
The attack comes as the United Nations refugee agency warned that foreign peacekeepers were now the only shield protecting Muslims in parts of the CAR from mass slaughter.
Freshly back from the conflict-torn country, Volker Turk, a senior official from the office of the UN High Commissioner for Refugees (UNHCR), said the scale of communal hatred was shocking.
Turk told reporters that he had travelled to Boda, southwest of Bangui.
"You have a Muslim community essentially besieged, with a no-man's land in between the Muslim quarter and the Christian community," he said.
"There would be a massacre were it not for Sangaris. Were it not for Sangaris, that Muslim community would no longer exist," he said, referring to the name of a French peacekeeping operation.
"We see a similar situation - and that has deteriorated over the last couple of days - in Bangui itself," he added.
Some 8000 foreign troops - 2000 from former colonial power France and most of the rest from the African MISCA force - are trying to disarm rival militias after a year of sectarian violence.
Thousands have been killed and around a quarter of the country's 4.6 million people displaced, most of them Muslim.
France has tried to rally international support for increased peacekeeping efforts in its former colony.
