"Up to one fifth of families in Afghanistan have been forced to send their children out to work as incomes have plummeted in the past six months with an estimated one million children now engaged in child labour," it said.
The London-based charity, which champions the rights of children worldwide, said it surveyed 1,409 households in seven provinces where it retained an operational presence since the Taliban (under UN sanctions for terrorism) swept to power in mid-August.
It estimated that 82 per cent of Afghans had lost income since the collapse of the former government, with a third of respondents saying they had lost all of their income and a quarter said they lost more than half.
A spike in prices that followed the power transition in Afghanistan left many Afghans struggling to get food.
Some 36 per cent said they were buying food in the market on credit, 39 per cent were borrowing it from better-off families and 7.5 per cent resorted to begging.