"The military administrator of Rutshuru territory had been receiving complaints from users of the Rutshuru-Goma road for some time," said Lieutenant-Colonel Muhindo Lwanzo, the administrator's chief of staff.

Six soldiers were arrested on Sunday, and an investigation is under way to identify possible accomplices, he said.

In addition, two soldiers were sentenced to death this weekend for murder and attempted rape, said Aime Umba, military auditor of the garrison at Goma, the provincial capital of North Kivu.

They are accused of killing two Pygmy children from the same family in Sake, northwest of Goma, during a dispute with a prostitute.

The children, aged eight and four, were hit by stray bullets and died instantly, said their father, Profit Elisha.

North Kivu is currently under emergency measures, with civilian authorities replaced by military and police governors, in a bid to restore order to the conflict-ridden zone.