File Photo: An Internally Displaced Persons camp in Bunia, in the Ituria region in eastern DR Congo. AFP
The same camp was attacked less than a week ago when 29 people were killed.
Red Cross coordinator Mambo Bapu Mance told AFP that 20 people were buried immediately in two common graves, while another two who died of their wounds were buried later.
He accused the armed group Cooperative for the Development of Congo (CODECO) of carrying out the attack.
The Kivu Security Tracker (KST), a respected US-based monitor of violence in the region, cited the same death toll.
The army spokesman in the region, Lieutenant Jules Ngongo, said the CODECO rebels were repelled but did not elaborate.
Gold-rich Ituri province has been plunged back into a cycle of violence since late 2017 with the rise of the CODECO militia, which has since split into rival factions.
Ituri and neighboring North Kivu have been under a state of siege since May 6, an exceptional measure to combat armed groups including CODECO and the Allied Democratic Forces (ADF).
Civilian authorities have been replaced by military and police officers.
Two other attacks took place overnight Saturday elsewhere in Ituri, leaving a total of nine civilians dead, civil society leader Isaac Nyakuklinda told AFP.