About 20,000 are former Rwandan soldiers and militia members ineligible for food aid, although they are fed by the refugees.
François-Xavier Nzuwonemeye is a former Rwandan soldier, who is chiefly known for his alleged role in the Rwandan Genocide.
Among the refugees are at least 40,000 former Rwandan soldiers and tens of thousands of militiamen who took part in mass killings of Tutsi civilians in 1994.
Tens of thousands of former Rwandan soldiers and Hutu militiamen now live in the camps and use them as bases for forays into Rwanda, those officials say.
A former Rwandan soldier received a 15-year sentence for the 1999 murders of eight Western tourists and a game warden.
Less than a year ago in the Mugunga camp, there were as many as 25,000 former Rwandan soldiers in uniform, United Nations officials say.
Now, in the civil war that has engulfed eastern Zaire, the former Rwandan soldiers and militia members have thrown their lot in with the Zairian military against the rebels.
But he has also embarked on an extremely risky mission whose success depends largely on cooperation from former Rwandan soldiers, Hutu gangs and Zairian rebels.
In at least two cases, when they were trapped at the border, they stormed the crossing into Burundi as Rwandan soldiers fired at them.
Emmanuel Habyarimana is a former Rwandan soldier and politician.