Ali Ahmad’s eyes fill with tears as he lifts his shirt to show deep bruises across his back.

While he was detained, Iranian officers struck him and accused him of spying, he says. “They used hoses, water pipes and wooden boards to beat me. They treated us like animals.”

He was speaking to the BBC earlier this month at Islam Qala on the two countries’ border, before crossing back over to Afghanistan. His name has been changed to protect his identity.

Iran - which says it hosts more than four million undocumented Afghans who fled conflict in their homeland - has been stepping up deportations for months. In March those without papers were given a July deadline to depart voluntarily, but since a brief war with Israel in June, the authorities have forcibly returned hundreds of thousands of Afghans, alleging national security concerns.

Daily returns peaked at about 50,000 people in early July, according to the United Nations – often after arduous journeys.

Ali Ahmad says Iranian officials confiscated his money and phone and left him without “a single penny to travel back”. He’d lived in Iran for two and a half years.

…

Iran’s crackdown has coincided with widespread accusations linking Afghans to Israel’s intelligence agency Mossad, including Iranian media reports that cite police sources claiming some individuals were arrested for espionage.

“We’re afraid to go anywhere, constantly worried that we might be labelled as spies,” one person, who wished to remain anonymous, told BBC News Afghan.

“You Afghans are spies”, “You work for Israel” or “You build drones in your homes”, are other frequent accusations, according to this individual.