By Martin Patience
BBC News, on the Afghan-Iranian border
Many Afghans head to Iran illegally in search of a better life
In a cavernous UN reception tent on the Afghan-Iranian border, eight men and a young boy sat and drank tea at a white plastic table.
Two of the men had bandages around their heads and another wore a neck brace.
The group of Afghans had been packed into a speeding vehicle on the way to the Iranian capital, Tehran, when they had swerved to avoid an oncoming vehicle.
"Our car then flipped," said Nowrous Haji Yakous, 22. "One of my relatives was killed in the accident."
The men were all then arrested by the Iranian police and an hour later were deported from the country because they had no relevant paperwork.
Afghanistan has long depended on its western neighbour Iran for work and sanctuary.
More than two million Afghan refugees poured into the country during the worst years of fighting - many of whom remain today.
But Iran is increasingly clamping down on the tens of thousands of young Afghan economic migrants who are smuggled across the border and then look for work.
Every day, hundreds of Afghans - mainly young men - are brought across the frontier on buses, deported from a country where they had hoped to find work.
According to UN figures, there were more than 400,000 cases of deportation in 2008.
Many of the workers have been deported more than once, effectively "recycling themselves" across the border, as one official put it.
Afghan workers can sometimes earn $1,000 a month in Iran - four or five times what they could expect to get in their own country.
It is an economic reality acknowledged by some officials in Herat.
"They just want to get jobs to provide for their families," said Shah Mohammed Mohik, director of the province's department for refugees and repatriation.
Mr Mohik says the Afghan government is trying to work with Iranian officials to make the process of getting work visas easier. He also says that the government must do more to create jobs for Afghans.
But despite the risks, there are still thousands of Afghans willing to cross the flat, unforgiving desert.
Many travel to Nimruz province in southern Afghanistan where people-traffickers offer to smuggle them across the border. The one-way trip costs about $400.
The journey for some refugees can be hazardous
But this illegal journey can take up to a month and is often extremely dangerous.
"Sometimes the Iranian police shot at our vehicles," said one man, who I had arranged to meet in a bustling restaurant in Herat city.
"We can't stop because we're illegal - they'll simply deport us. We spend a lot of time walking - skirting around checkpoints before getting into another vehicle. But some people die from thirst and hunger.
"The thieves also wait for you as you walk. And if they see you have good shoes, or a good watch - they'll rob you."
Of the hundreds of economic migrants deported from Iran every day, most are given a cup of tea and a biscuit and are then expected to return to their home towns and villages under their own steam.
But a few are too young or too sick to look after themselves and are taken to a UN holding centre for vulnerable deportees on the outskirts of Herat city.
Eight-year-old Abraham is one of them. He said his parents lived in Iran and sent him away to work on his own - hawking chewing gum on the streets.
The Iranian police picked him up and, because he was Afghan and did not have any paperwork, he was deported.
"I miss my family," said Abrahim. "There's nothing to do here."
The UN has put out appeals on Afghan TV but no relative has come forward for Abraham. He has effectively been left unclaimed.
But many Afghans believe the cost of travelling to Iran is worth it.
And with the beginning of spring - thousands more will be starting their journey.