Gaborone, Botswana - Botswana's government has come under fire over the building of a diamond mine with deposits worth $4.9 billion (R52 billion), which President Ian Khama is scheduled to open on Friday.

Khama will inaugurate the Ghaghoo mine in the country's Central Kalahari Game Reserve, on the ancestral land of the Bushmen who have been evicted from the area.

“The official opening ... is tomorrow morning. His Excellency President Ian Khama will officially open the mine,” said Ghaghoo's Batlhalefi Leagajang.

Botswana is one of the world's largest diamond producers, and the Ghaghoo mine is expected to yield more than 20 million carats, making it one of the world's largest mines.

Botswana's government has brushed off criticism of the evictions, saying the proceeds will be used to provide better schools and health facilities for Bushmen outside the reserve.

But the criticism intensified on Thursday, with rights group Survival International accusing the government of a “relentless push” to drive the Bushmen off their land.

“The Botswana government has repeatedly denied that the illegal and forced evictions of the Kalahari Bushmen ... were due to the rich diamond deposits,” Survival International said.

“It justified the Bushmen's evictions from the land in the name of 'conservation'.”

“The mine opening has ... exposed Botswana's commitment to conservation as window dressing.”

The Bushmen have won a series of cases against the government, and several hundred of the thousands expelled have been allowed to return.

But activists say their life is made difficult for the returnees, who are treated like poachers for hunting food. - Sapa-AFP