By Mark Doyle
BBC world affairs correspondent
Armed unrest in the Central African Republic has caused thousands of people to flee to Chad in recent weeks.
Chad is home to hundreds of thousands of refugees
Sources in the region speak of a nascent rebellion against the CAR government of General Francois Bozize.
The refugees say they were caught in the crossfire between forces loyal to General Bozize and others linked to the government he overthrew in 2003.
They say they are fleeing armed men who attack villages, steal possessions and in some cases kidnap children.
Refugee flows are often the first indication outsiders have of what is happening in the more remote parts of the world.
An estimated 5,000 people are now known to have fled the north-west of the Central African Republic in the past three weeks.
Hundreds of thousands of refugees are already living in the countries of this region, having escaped conflicts in Sudan and Democratic Republic of Congo.
A new rebellion would only exacerbate the situation.
Bruno Geddo of the United Nations High Commissioner for Refugees (UNHCR) said the refugees from the Central African Republic were frightened and in great need:
"They are in poor condition because they have walked sometimes for days. They have fled through the bush," he said.
"Some of them have been wounded. Some of them are exhausted. Many children are in particular need of care."
Sources in the region say that in recent months an embryonic guerilla movement has been targeting government police and army posts in the north-west of the country.
Forces loyal to the government have responded by attacking the perceived supporters of these rebels, the sources say, and innocent civilians have inevitably been caught up.