The crisis in Afghanistan is a "recipe for human trafficking", Christian charity CARE has warned.
The UK has promised to resettle up to 20,000 Afghan refugees over the next five years, with the first 5,000 by the end of 2021.
But CARE fears that people desperate to find any way out of the country will resort to unofficial channels, leaving them at "acute risk" of exploitation.
Lauren Agnew, Human Trafficking Officer for CARE, said that traffickicking victims would be vulnerable to abuse, sexual exploitation, forced labour and domestic servitude, working for little or no pay and possibly in squalid conditions.
She warned that women are particularly at risk.
"The desperate situation in Afghanistan is a recipe for human trafficking," she said.
"Afghan citizens face an acute risk of exploitation by traffickers as they seek to flee violence and persecution under the Taliban regime whilst nations including the UK only accept a limited number of refugees.
"Afghan women, particularly fearful of what life may look like under new political leadership, are particularly at risk.
"Aware of attacks on their rights, they will want to try and escape Taliban control and oppression and may, in desperation, turn to illegal means of leaving the country."
She called on Western governments and NGOs to "do all they can whilst officials are still on the ground to prevent refugees from falling into the hands of exploitative groups".
"They must also step-up efforts to identify victims of human trafficking and modern slavery in their own jurisdictions in the months ahead, moving quickly to free them and provide them with access to support," she said.
