* Bella ethnic group has served Tuaregs for centuries
* Campaigners call arrangement slavery
* Tuareg leader in camp says his group unfairly singled out
By Misha Hussain
GOUDEBOU, Burkina Faso (Thomson Reuters Foundation) - Ten-year-old Atahib goes to school in the Goudebou refugee camp in the savannah of Burkina Faso, not hoping to become a teacher or a doctor like his classmates. He wants to learn so he can better serve his Tuareg masters.
Each day, Atahib wakes up before the Muslim morning call to prayer to help his mother with her chores - unpaid work that people from their Bella ethnic group have been doing for the ligher-skinned Tuaregs for centuries in Mali, Niger and Mauritania.
Campaign groups call the arrangement slavery - though Tuaregs in the camp insisted the Bella were free to take their chances and leave.
At 7 a.m., Atahib walks along a dusty track to join the rest of the children in school.
"Reading and writing will help me to do chores like going to the market so that I don't get ripped off," he said in a barely audible voice, his eyes fixed on the ground.
His masters fled to Burkina Faso after a rebellion erupted in their home, northern Mali, two years ago. Tuareg separatists and Islamist rebels seized control of desert territory in 2012 until a French-led campaign seized it back.
That was followed by revenge attacks on anyone associated with the rebellion, forcing hundreds of thousands to flee, some crossing the border to neighbouring Burkina Faso. Tuaregs took with them their livestock and Bella workers.
Slavery was formally abolished in Mali after independence from France in 1960. But thousands of Bella still work without pay in Tuareg households - preparing meals and cleaning, and looking after livestock, say campaign groups.
They receive food and shelter but are regarded as their masters' property and are often named after his favourite food or a day of the week, anti-slavery campaigners say.
For some Bella children, their new life may provide an opportunity for change: in Mali, children like Atahib would never have had an education. The school in the Goudebou camp is trying to redress this cultural inequality, providing Bella children with daily classes, just like their Tuareg peers.
"In school, the children realise even though there are differences, they share a lot in common. Some of the Tuareg children even see that those they consider subservient are just as bright," said Oscar Nkulu, community officer for UNHCR.
Though some progress has been made, many Bella children see their future as workers in the households of Tuareg classmates.
"When I grow up, I want to be a servant," said Aminata, doing everything to avoid eye contact - a contrast to buoyant Tuareg kids who want to be humanitarian workers or politicians.
"PRISONERS OF THEIR OWN MIND"
Ibrahim Ag Idbaltanat, president of Temedt, an anti-slavery organisation in Mali, said slavery remains common in the north. Many born into it see no future beyond their masters' walls.
"They have never had the taste of freedom so for them this life is normal. They are prisoners of their own mind," said Ag Idbaltanat.
"Those that think about running away are afraid the authorities will return them to their masters with terrible consequences," he said.
In the Goudebou camp, only a few acacia trees scattered around the savannah can withstand the Sahel sun. Pastoralists take refuge under their branches, while Tuareg women lie in the shade of their tents. But the Bella are working.
The UNHCR's Nkulu said attitudes were slowly changing, particularly in school where children mixed and played together.
"Before the Bella were hiding, now they are coming out. The Tuaregs were confrontational, and now apologetic," said Nkulu.
Mohamed Ag Artegal, head of a Tuareg community in Goudebou, said other ethnicities kept slaves and the Tuaregs were being unfairly singled out for criticism.
"In the past, if you were black, you had nothing. No land, no livestock and there are no jobs. You were obliged to work for someone," said Ag Artegal, adding that the Bella were free to leave if they wanted.
But with no food and water in northern Mali's vast desert, and scarce jobs in its few towns, the odds are stacked against runaways.
In Mali, little is being done to tackle the problem, said Sarah Mathewson of the London-based Anti-Slavery International.
A post-war election last year unlocked $4 billion of foreign aid but most funding is being channelled towards security.
"Donors see security as a bigger priority than eradicating slavery," Mathewson said. "But if you are talking about fostering sustainable peace then slavery needs to be addressed." (Editing by Daniel Flynn and Andrew Heavens)