At least 22 people were killed when two Ugandan military helicopters crashed in east Democratic Republic of Congo on Tuesday, a Congo army spokesman who did not wish to be named told Reuters on Wednesday.
Uganda sent troops to its central African neighbour in December to help fight a violent rebel group known as the Allied Democratic Forces (ADF).
"The [Uganda People's Defence Force (UPDF)] have not yet told us the circumstances of the crash," the spokesman said without providing further detail.
UPDF spokesman Felix Kulayigye confirmed one helicopter crash and said "there were fatalities, but I don't have any extra details at the moment".
The ADF is among several militias wrangling over land and resources in Congo's mineral-rich east over the past decade, a conflict that has claimed thousands of lives and displaced millions.