As desert sands relentlessly wipe away more and more arable land in arid Burkina Faso and Mali, leaving people hungry, access to fertile farming land is becoming increasingly worth fighting, and even dying for.

On Burkina’s western border with Mali, nine people died in the village of Ouarokuy on 1 July, following clashes with villagers from Ouanian, seven kilometres away and over the border in Mali.

“It’s an area where lands are fertile - unlike most parts of both countries,” said Elie Zan, an official in Burkina Faso’s internal affairs ministry.

Mud and thatch grain stores were destroyed and burned in the rampage, with traditional hunters, or ‘dozos’, who typically carry locally manufactured guns, leading the fight on both sides.

Mali and Burkina Faso are two of a chain of Sahelian countries that link west to east from Mauritania to Sudan. Their territories form an unbroken line that skirts the southern fringes of the Sahara desert.

But each year desertification eats up a few more metres of precious farming and grazing land, forcing people to struggle ever harder to eke an existence from this fragile earth.

This week in Mali’s east-flank neighbour Niger - another link in the Sahelian chain - President Mamadou Tandja called on his people to plant trees to battle the encroaching desert dusts.

The combined effects of years of drought and a rare locust plague in 2004 last year caused a hunger crisis across the Sahel, which has four out of the five of the world’s poorest countries, according to the United Nations.

But access to land is a chronic problem in regional super-power Nigeria, too. In the central plateau region hundreds of people are regularly killed and tens of thousands sent running for their lives over land disputes.

To calm the situation along the Mali-Burkina border, security forces, traditional leaders and local government officials have been sent to visit the quarrelling villages on both sides, and authorities have called for an end to any new land clearing, fearing that it could spark more violence.

Mali and Burkina Faso have fought over the demarcation of this 1,285 km stretch of border before, in 1974 and 1985. After an international court ruling, that border is now being painstakingly marked out, but the high cost of the process means only 600 km have been etched on to the cartographer’s plan in the last three years.

Government officials in Burkina Faso say the clashes in July were essentially a local issue born out of traditional systems of land allocation.

For generations, and before the existence of an international frontier erected between the two villages during the colonial era, the residents of Ouanian, now in Mali, had called on their neighbours in Ouarokuy, in Burkina Faso, for land to farm.

The deal was never written down, indeed no purchase of land was made. But the beneficiaries would be expected to present some of their crop as a gift.

That arrangement is mirrored time and time again across the Sahel. But as populations in this part of Africa are some of the fastest growing in the world, as the desert continues its march south, fertile land is falling in short supply.

“We remind the populations on both sides of the border that they are condemned to live together and to understand one another,” wrote Abou Sow, the Governor of Segou in Mali, in an article published in a local newspaper earlier this month.

“So I invite them to peaceful cohabitation, dialogue and permanent consultation between these populations who speak the same language, are from the same tribes and share the same values.”