Suspected Ugandan rebels killed at least 12 civilians on Monday in eastern Democratic Republic of Congo authorities and local human rights groups said.
The rebels used machetes in the latest in a series of targeted attacks over the last 18 months.
Rebels from the Allied Democratic Forces (ADF), a militant group originally from Uganda that has operated in the border region since the 1990s, carried out the killings in the village of Mamabio, 50 km (30 miles) north of the commercial centre of Beni, said territorial administrator Amisi Kalonda.
"The bodies were found lying in different places. (The rebels) also ransacked the health centre," said Kalonda, who said 13 people were killed.
The Centre of Study for the Promotion of Peace, Democracy and Human Rights, a local organisation that documents violence in the region, confirmed the killings in a statement, saying 12 were killed.
Hundreds of civilians have been killed in dozens of raids near Beni since October 2014, defying repeated offensives by Congolese and UN peacekeepers against the ADF, who are believed to have only several hundred fighters.
A UN panel of experts and independent analysts, however, have questioned the DRC government's near blanket attribution of responsibility to the ADF, saying that other armed groups are likely involved.