1110 GMT August 10, 2020
The incident happened overnight Thursday at Sange, in the territory of Uvira in South Kivu Province, they said, AFP reported.
"The person responsible is a drunken member of the Armed Forces of the Democratic Republic of the Congo (FARDC) who opened fire on at least 20 civilians who crossed his path," a prosecutor in Uvira said.
Captain Dieudonne Kasereka, the army's spokesman in Uvira, said "the toll to our knowledge is 13 dead", and said the gunman was on the run and still armed.
"An army delegation and a UN team is in the area to calm the population, which is demonstrating against the army," he said.
Angry residents blocked Highway 5, which runs through the area, using branches and burning tires.
They also displayed the 12 bodies, wrapped in funeral shrouds, at a busy crossroads, blocking traffic, several witnesses told AFP.
NdaburwaRukalisa, a local leader in Sange, said the soldier was a member of the 122nd Battalion of the FARDC, based locally, and was "in a state of drunkenness" at the time.
Nine people were hospitalized in a "critical" condition, he added.
The provisional toll of 12 dead was confirmed by witnesses, while a judicial source said a two-year-old girl was among those who died in the rampage.
Sange is located 80 kilometers (50 miles) from Bukavu, the capital of South Kivu Province.
The highway connects Uvira, the province's second-largest town, with the border with Burundi.