HARARE; The chairman of the Kimberley Process has agreed to allow Zimbabwe to sell diamonds from its disputed Marange fields, deputy mines minister Gift Chimanikire said on Friday.

The Kimberley Process, created to prevent the trade in "blood" diamonds that fuel armed conflicts, normally takes such decisions by consensus at its regular meetings.

But the current chairman, Mathieu Yamba of the Democratic Republic of Congo, appears to have taken the decision unilaterally, raising questions among industry groups and watchdogs about the validity of the decision.

"Permission for sale was issued by the KP chairman," Chimanikire told AFP. "But I do not know when the actual sale would take place."

He said the decision was apparently taken in February, when Zimbabwe Mines Minister Obert Mpofu travelled to the DRC to meet with Yamba.

Kinshasa holds the rotating chair of the Kimberley Process, and has close ties to President Robert Mugabe.

The Marange fields, touted as Africa's richest diamond find of the decade, have been at the centre of a years-long controversy over mining rights and abuses by the military.

The military seized control of the fields near the Mozambican border in late 2008, violently evicting tens of thousands of small miners and then beating and raping civilians to force them to mine the gems.

Human rights groups say about 200 people were killed, and Kimberley investigators later documented "unacceptable and horrific violence against civilians by authorities", prompting a ban on exports of the gems.

Kimberley allowed two special sales of diamonds last year, but no agreement has been reached on whether to allow general exports of the gems.

"It's very disappointing," said Elly Harrowell, diamond campaigner with Global Witness, a watchdog that is party of the Kimberley Process.

"All decisions made in the KP are made on the basis of 100 percent consensus between all members," she said. "For the chair to unilaterally declare that this decision has been made against the will of numerous members.

It is very worrying."

The World Diamond Council, a global industry group, has warned its members not to trade in the gems because the United States, Canada, Israel and the European Union have indicated that the diamond sales should not yet be permitted.

The council "advises members of the international diamond industry to refrain from trading in and exporting goods from the region until the situation and the status of these goods becomes clearer."