Aid workers have unearthed the remains of 12 people who they say were murdered by international peacekeepers in the Central African Republic in 2014.

The troops, from the Republic of Congo, were part of a peacekeeping mission — first under the auspices of the African Union, then the United Nations — aimed at ending a civil war that left thousands dead beginning in late 2012. Human Rights Watch had previously reported on the role Congolese peacekeepers played in “enforced disappearances,” but the Congolese government “has taken no action toward credible investigations or justice for these crimes,” according to a new report by the group released Tuesday.