At least 24 people were killed and more than 100 were wounded after Chadian soldiers opened fire on civilians in the Central African Republic of Bangui.
The incident took place on Saturday, when the troops were escorting a convoy of Muslims back to Chad.
"When they got to the PK12 neighbourhood, they suddenly started shooting. People panicked and started running and
ducking for cover," Sebastien Wenezoui, a spokesman for the country's Christian militia, told Reuters news agency on Sunday.
An officer with MISCA, the African Union's support mission, told AFP news agency that it was unclear what had happened. The official, who requested anonymity, said the incident occurred in a mainly Christian district in the north of Bangui and that the casualty toll could rise.
Later on Sunday the mayor of Begoua, Odette Dombolo, told reporters that 24 bodies had been identified and more than 100 people were wounded. Previously, it was claimed that eight people had been killed.
Chadian soldiers have previously been accused of siding with Muslim fighters, known as Seleka.