Authorities in the Democratic Republic of Congo said the remains of at least 20 people had been found in North Kivu during the weekend.
The remains were discovered in an area that was under control of the ADF (Allied Democratic Forces a rebel militia with links to the Islamic State group), and had ben retaken by the Congolese army this year.
Residents of Ndoma and other villages located nearby alerted the authorities that they had found bones and clothes in the field, in an area normally used for planting cocoa.
The military deployed a team with officials, police, forensic investigators and others to search the area.
Muyisa Kambale Sindani, a representative of the nearby village of Kilya, said the remains would be buried with "dignity".
He said that the bones of at least 20 people were found, but that it would not be possible to extend the search due to the precarious state of security in the region.
Conflict has been simmering in eastern Congo for decades as more than 120 armed groups fight for power, influence and resources and some to protect their communities.
The ADF has been largely active in North Kivu province but has recently extended its operations into neighboring Ituri province and to areas near the regional capital, Goma.
The ADF rebels are accused by the U.N. and rights groups of targeting, maiming, raping and abducting civilians, including children.
“There are innocent people who have been buried here. This is really a mass grave,“ said Cap. Anthony Mwalushayi, spokesperson for the military.
In addition to the bodies of civilians, the army said that clothes and remains of some soldiers were also found in the area .
Residents of the area that helped in the search, demanded justice and more protection from the government.
"We demand justice be done so that the perpetrators of this massacre answer for their actions and set an example for other rebels to stop killing us unfairly,” said Richard Kakule, a farmer from Ndoma.
After the forensic and experts collected the remains and put them in white bags, local residents organized a small ceremony where they sang while burying the bodies with their own hands.
The Uganda-based ADF rebels have been active in eastern Congo for decades and have killed thousands in the region since they resurfaced in 2013.
Earlier this year, the United States offered a reward of up to $5 million for information that could lead to the capture of the group’s leader, Seka Musa Baluku.