From the Telegraph UK, writer Phil Hazlewood profiles one such family.
"We came here to earn money," said Chaman Gul, leaning on the handle of a shovel in a pile of wet sand at the Gahiz brick factory, which makes 42,000 bricks every day for building sites from Kabul to Bamiyan.
"My five sons are here and I have four daughters at home in the village."
Chaman is 36 but looks two decades older. Four of his sons - Omar, 15, Amin, 13, Taza, 12, and 10-year-old Anam - squat nearby, looking up occasionally as they fill cast-iron brick moulds.
His fifth, Stana, 18, is busy elsewhere on the site.
The children, whose small footprints are left in the powdery dust amid tyre and hoof marks, are not playing though.
They are working and Chaman's youngest son - four years below the minimum working age in Afghanistan - is by no means an exception.
Elsewhere in Kabul, other school-age children can be seen in grimy workshops, pushing wheelbarrows, struggling with heavy sacks or, unseen behind the walls of housing compounds, weaving carpets by hand on large metal looms.
UNICEF said in 2007 that a quarter of Afghan children aged between seven and 14 worked, despite legal and constitutional protection and Afghanistan being a signatory to the UN Convention on the Rights of the Child.
The Afghanistan Independent Human Rights Commission (AIHRC) estimates that 60,000 children are currently working in Kabul alone.
At the brick factories, children spend their days in the choking air of dust and acrid charcoal smoke from the kilns, stacking and sorting rectangles of wet bricks laid out to dry in long rows.
Poverty, inflation and the human cost of war - death or disability among parents - mean they must work to feed their families, said Nadery.
Even when parents do have jobs, and free government schools exist, attendance is often dependent on whether a family can afford pens and paper, he added.