Zimbabwean children as young as seven are walking alone through hostile territory to cross the South African border in a bid to escape crushing poverty at home, research by Save the Children has revealed.

These children, many of whom are recently orphaned, see South Africa as a land of opportunity where they can find work and a place at school, according to the aid agency's latest report, Children Crossing Borders. 

But many of these children who arrive in South Africa unaccompanied have no form of identification and cannot register for help from the authorities.

Only one in three children of the children interviewed during the research was in school and most were forced to work in unreliable and dangerous jobs. They live in squatter camps and on rubbish dumps where many must beg for food.

The research found that children are forced to pay bribes to unscrupulous guides to enter the country and many were beaten and robbed by these 'guides'. Half of the children surveyed had paid a bribe, 80% of those to a 'guide' and 14% said they had been assaulted while attempting to cross the border. 

South African law obliges authorities to protect and care for these children, but the sheer number crossing the border from Zimbabwe and other southern African countries like Mozambique is overwhelming. Under-funded and ill-equipped communities in South Africa simply cannot cope with the influx of unaccompanied children. 

"These children see South Africa as the Promised Land," said Dominic Nutt of Save the Children. "But the dangers they face travelling long distances alone and then once they reach South Africa are horrendous. They are poor, hungry, young and highly vulnerable and are easy prey for criminals or people seeking to exploit them.

"It's hard to imagine how bad the lives of these young people must be that they leave home, alone, to face such terrifying risks."

Save the Children is planning to build a series of shelters along the border where children can be cared for, fed and schooled in safety without fear of being forcibly returned.