At the Islam Qala crossing point in Herat province, western Afghanistan, Talibshah, who did not to give his family name, said he had been working in agriculture northwest of Tehran.

He was cheated by money changers at the border and was trying to figure out how to get back to Sar-e-Pol province in the north, hundreds of kilometres away on difficult, mountainous roads.

Talibshah's work in Qazvin in northern Iran helped support seven people -- his mother, father, brothers and sisters -- at a time when drought had made farming difficult, if not impossible, back home.

"I don't know whether I will be able to find a job or not. We are left without prospects," he told AFP.

"If I don't find a job here, I'll have to emigrate again. We have no choice. We can't starve," he added.

- Funding shortfall -

The United Nations has warned that nearly half of Afghanistan -- 21.9 million people -- will need humanitarian aid this year.

Since February 26, the country has been hit by fresh clashes with neighbouring Pakistan to the east, which have killed at least 56 civilians and forced about 115,000 from their homes.

The UN refugee agency's representative in Afghanistan, Arafat Jamal, said there was "no good choice" for those coming back.

"They're fleeing war in Iran and coming to a country that is also itself at war," he said. "In other words, these people are coming into a country that is wracked by drought, that has unemployment, and that now has conflict inside it."

Since the war began in the Middle East on February 28, about 1,700 people have returned every day. But the UNHCR is expecting bigger numbers in the future if there is no let-up in the conflict.

The agency is ready in terms of staff and infrastructure to receive those leaving Iran but funding was lacking for the relief effort, said Jamal.

- '50 times greater' -

At the Islam Qala border post, more people arrived on Tuesday than the previous week, said an AFP correspondent on the ground.

Families crossed quickly, their faces expressionless, with one or two suitcases holding their meagre belongings.

Mohammad Kabir Nazari, 48, had been working for the last 11 months as a security guard in Tehran, and was in the country during the 12-day war last June.

He described the latest strikes as "50 times greater".

"Missiles were coming from all sides, every day," he said. "For Afghans, there was no shelter. The situation was very bad."

Nazari, originally from Ghazni province in eastern Afghanistan, said he had been travelling to Iran for the last 32 years.

Then, the markets were busy around the Persian new year, Nowruz, and for the end of Ramadan but were currently empty, he added.

The slowdown in Iran's economy has consequences for the many Afghan migrant workers: one friend of Nazari told him he had been sacked with other Afghans, and forced to return.

- 'Waves and waves' -

Naeemullah Rahimi, 24, was also working as a security guard, at a factory in the Tehran suburbs. He said he was forced to shelter from air strikes in the basement.

"When we saw that the situation was very bad, we had to come back to Afghanistan," he said.

Jobs are scarce in his home province of Wardak in central Afghanistan.

"I don't know what to do," said Rahimi. "But if I find a job, I'll work."

The UNHCR's Jamal said "waves and waves" of people have been deported to Afghanistan from Iran and Pakistan since September 2023. Last year alone, 2.8 million Afghans returned.

"That was the largest such movement in the world," he added.

"If we start to experience similar numbers this year, will Afghanistan really be able to cope? Perhaps, but it needs international support.

"We cannot afford to let Afghanistan fail," he said, warning that forgetting the region will had an even more destabilising effect in the world.