In one decrepit corner of the street-corner daara, or Islamic boarding school, about 30 ragged children are on a morning break. For a group of five to 15-year-olds they unusually timid and quiet. They are filthy, pathetically thin and look weak. The heads on their tiny frames seem old before their time.
There is little about these boarding schools that Harry Potter would recognise - except perhaps for the wizardry, for there is plenty of hoodwinking and trickery afoot. This is boarding West African style for the poorest of poor parents who think that their children are going to be educated and looked after. What happens instead is that tens of thousands of unsuspecting children are lured, pied-piper style, from the villages of Senegal, Mali and Niger into a modern form of slavery.
Sitting in the shade some distance away, their headmaster, the marabout, explains why his charges are not playing football on their day off. "It would interfere with their Koranic studies," he says. No one demurs. There is such extreme poverty in Senegal, he insists, that the hardships the boys endure at the daara prepare them for a life of suffering ahead.
Ahmed is 10, but unlike normal Senegalese children, has difficulty cracking a smile. He waits until the marabout is out of range before talking. "I've got a headache," he says, "I'm always tired, we have to get up early to learn the Koran and then we go out to beg. Every day we must bring back CFA500 [£5]."
What these children have entered is a system of indentured servitude in which they are exploited by teachers who live off what the children solicit on the streets.
Child begging is illegal in Senegal. But as across much of West Africa the law, where it exists, is laughed at. Few politicians seem ready to take on the mullahs in an overwhelmingly Islamic country where the mosque remains the most effective vote-getting machine.
Young Ahmed (not his real name) leads me to the crude breezeblock dormitory he shares with the other boys. Filthy bedclothes are strewn everywhere and the place is alive with mosquitoes and cockroaches. The marabout's horse is tied up just outside and in the heat of the afternoon there is a foul smell from the animal's dung.
Known across West Africa as talibés, tens of thousands of poor children are entrusted to marabouts for their education. Destitute parents are sometimes paid off by child traffickers, others let go freely. But the schooling involves several hours every day learning the Koran by heart in Arabic without formal education. Most emerge at 16 illiterate. They have spent most of their school years begging.
For generations the daaras were based in villages deep in the countryside. But severe drought has forced them off the land. With no state-funding for daraas, the marabouts have, in recent years, been moving en masse to the cities with their young charges.
Today they are everywhere in West Africa, especially in the downtown areas of cities, hanging around traffic lights, outside restaurants or on beaches - anywhere there are tourists. They walk barefoot for hours every day seeking scraps to eat, while bringing back money for the marabouts. In Senegal alone there are estimated to be upwards of 100,000 talibés. And they are heartbreakingly young, averaging 10 years of age, underweight and weak from poor diet and non-existent healthcare.
On a dirt road on the outskirts of Thiès, about an hour's drive from Dakar, an aid worker from the local charity Tostan looks for talibés. She is Khadid Bathily. Her agency is sponsored by Anti-Slavery International, one of the three charities being supported in this year's Independent Christmas Appeal. She has identified around 700 of these children in her database in the past few months.
Khadid, a devout Muslim, has organised about 45 neighbourhood families to "adopt" a talibé each. They agree to wash, feed and clothe the young boys and to see to there healthcare all with the reluctant agreement of the marabouts.
We find four boys hanging around with their begging bowls: Usman, Aliou, Mohammed and Malick. Not one of them knows his age or where he is from. Two have had short visits from their parents, over a year ago. They complain of being sick with headaches all the time. "It's from being hungry and walking for hours every day in the sun while begging," says Khadid.
Back at the daara Ossman, a well-groomed marabout, insists that the boys are all well looked after and only beg to pay for their clothing and schooling.
"I take nothing," he insists, "I am a poor man." It is hard, somehow, to believe it.Reuse content