The army in the Democratic Republic of Congo says it will punish any soldiers in contact with a largely Hutu rebel group linked to the 1994 Rwandan genocide.
The army said anyone – regardless of rank – who broke the ban on dealing with the FDLR militia would be arrested.
The announcement follows pressure from the United States on both Congo and Rwanda to lessen tension between them.
Rwanda is widely believed to have set up the Tutsi-led M23 rebel group to counter the FDLR – Rwandan authorities have always denied allegations of supporting the group.