There is no running water and no food or shelter other than what they have been able to carry with them: relief rations and plastic sheeting handed out by the United Nations in the camps. There are an estimated 55,000 Rwandan refugees stranded between the camps they abandoned last week and the border which was sealed by the Tanzanian government on Friday.
Members of Rwanda's Hutu majority, they fled their homeland in July after Tutsi-dominated rebels overthrew Rwanda's extremist Hutu regime. Now they are once again in flight, this time from ethnic tension in their country of asylum. There has been growing unrest among Burundi's Hutu majority and Tutsi minority. Hundreds have been killed in the capital, Bujumbura, and around the countryside. An attack on Majury refugee camp in northern Burundi the weekend before last left a dozen dead and 20 wounded. Soldiers from Burundi's largely Tutsi army allegedly carried out the raid.
There were 100,000 Rwandan refugees living in four camps in Ngozi province; now Magara camp is deserted and two more are emptying. It is not clear how many more refugees will leave but many said they were too frightened to stay.
Though many people are illiterate, radios are common and there is a constant traffic of information between one hillside community and another. Having heard of the attack on Majury camp, the refugees' anxiety was further increased by reports of hundreds of French and Belgian families being evacuated because of unrest in the capital. If the bazungu, or whites, were leaving, they reasoned, they knew what they were doing.
"Burundi no longer wants us," said Innocent Bagengana, who last year fled Butare, in southern Rwanda, with his wife and children. "The military think we're creating trouble here. We can't go home because the new authorities think all refugees are interahamwe [Hutu extremist militiamen]. So now we're fleeing again".
There are already 600,000 Rwandan refugees in camps just over the Tanzanian border. The Tanzanian government insists a new influx of Rwandans would make the country's refugee problem unbearable. On Thursday, 3,000 Rwandans crossed the border before it closed. Tanzania, though under pressure from the UN High Commissioner for Refugees to admit more, is not obliged to take in people who have already found a country of asylum.
So they squat by the roadside, cooking, chatting in disconsolate groups and sleeping in makeshift huts. The leaders of the largest group, which has come to rest 40 miles from the Tanzanian border and just short of a Burundian army road-block, said they would set up camp where they were. They have started to clear the bush on either side of the road and chop trees for firewood.
"We were afraid people would come into our camp with guns, so we left," said Jean-Baptiste Niyomunyembabazi, who set out from Magara on Thursday. "It's not safe for us to go back, so what can we do?'' He said it was too dangerous for him and his wife to return to Rwanda, though he denied they played any role in last year's ethnic conflict, in which 500,000 Tutsis and moderate Hutus were killed by extremist Hutu militias following the death of the Rwandan president, Juvnal Habyarimana, a year ago this week. Hundreds of thousands of Hutus fled into neighbouring countries ahead of the victorious Rwandese Patriotic Front (RPF) rebels, who pledged to end the genocide.
However, such is the power of collective denial among the Hutu refugees from Rwanda that all denied genocide took place in their country. They insisted Hutu militias only acted in self-defence and that the killing was the inevitable result of civil war. Some, like Mr Niyomunyembabazi, said they had family members murdered in revenge attacks by RPF soldiers.
The refugees interviewed by the Independent at the weekend, all from the university town of Butare, said there were no interahamwe among their number. Tutsis, they contended, were no more victims of the massacres than were Hutus.
Some of the worst of last April's massacres took place in Butare. Survivors have told how Hutu militiamen threw men, women and children into pits filled with flaming tyres and how whole communities were butchered with machetes and grenades while they hid in church centres.
A year after the start of Rwanda's genocide, the country's two ethnic groups are still no nearer reconciliation.
While the Tutsi-dominated government pursues those deemed guilty of the atrocities, countless thousands of Hutu refugees languish in camps or wander the roads of neighbouring countries.