During decades of conflict, millions of Afghans have crossed into Iran to escape violence and a shattered economy.
The Taliban takeover of Kabul in mid-August has compounded the crisis - disrupting international aid flows even as a severe drought has left more than half of the population facing acute food shortages, according to the United Nations.
But despite the dire conditions awaiting them, Iran continues to force Afghans back over the border.
Aid agencies are warning of a potential crisis in neighbouring countries. That is as thousands of people continue to flee Afghanistan.
Al Jazeera’s Rob McBride travelled to the Afghan border town of Islam Qala, which has seen a recent surge of people crossing in both directions.