Today, the crossing is taking on a new life - as an increasingly important transit centre for humanitarian aid.

The World Food Programme has already sent dozens of trucks filled with food supplies through here, to be distributed in north Afghanistan.

Unicef, the United Nations Children's Agency, sent its latest convoy through this border post. The three trucks had set off from government warehouses in the eastern town of Turkmenabad, about seven hours' drive north of the border.

Aid mission

The scenes on the morning of the departure are hectic. "This generator can go," shouts Unicef logistics officer Maurice O'Neill, as he strides through the warehouse, dodging forklift trucks and weaving past workers.

Up to 7.5 million Afghan refugees face starvation before winter

Mr O'Neill has been in this situation countless times before. He has worked in humanitarian emergencies in countries across Africa and Asia, including an 18-month stint in the Afghan capital, Kabul.

In this Unicef consignment, there are syringes, vaccines, oral rehydration salts and aluminium cooking sets.

These goods will be able to help only a limited number of Afghan families through the difficult months ahead. But they will play a role in the wider relief operations being undertaken by aid organisations from other countries that neighbour Afghanistan.

Road to the border

Loading is completed in around four hours. But it will be several more hours before the three Afghan trucks finally pull out of their depot on the edge of town and head south.

The road they take runs near the Uzbek border, and follows the Amu Darya river.

There is a narrow strip of arable land on both sides of the road that is irrigated by the river. But the dust in the air, which dims the light of the setting sun, is a reminder that the desert is only a few hundred metres away.

Beyond the town of Atamurat the vegetation thins out, the asphalt road comes to an end, and the dirt track slows progress down to a crawl.

Unicef used to work inside Afghanistan before its staff were advised to leave

It is three in the morning by the time the convoy arrives at Imam Nazar. The border will not open until eight, so the drivers bed down in their cabs and snatch a few hours sleep.

At dawn the isolation of the place is revealed - a grey sky, a few scattered buildings, a handful of border guards and a fence marking the frontier stretching out across the desert.

There is no influx of Afghan refugees here. Turkmenistan has made it clear that they are not wanted. But the inhospitable terrain on either side of the 800-km border is a more compelling reason for them not to come in this direction.

Some have gone to Iran or Pakistan. The vast majority of those in need are, however, still in Afghanistan.

Forced to leave

The Unicef office in the north of Afghanistan used to cover nine provinces with a population of nine million.

It had its problems - crumbling infrastructure, and the extra burden of half a million people who had fled to the area to escape fighting or the consequences of a three-year drought affliction.

But after the terrorist attacks of 11 September, Unicef international staff had to be pulled out and now its north Afghan operation is being run largely from Turkmenistan.

The three Unicef trucks that this morning creep across the border are playing their small part in keeping that operation going.