A major U.S.-based diamond trading network says it will not allow members to knowingly trade stones from the controversial Marange fields of eastern Zimbabwe.
Rights groups say Zimbabwe's military, which controls the fields, killed some 200 people and forced villagers into hard labor.
The Rapaport Diamond Trading Network said Monday it will expel any of its 10,000 members who buy or sell Marange diamonds, and will publish their names.
A statement urged members to obtain written assurances from suppliers that the diamonds are unconnected to the controversial diamond source.
It said that although the global diamond watchdog, The Kimberley Process, certified the diamonds, it did not guarantee human rights were not violated.
Rejoice Ngwenya, a political analyst in Zimbabwe, told VOA she believed Rapaport's ban will have little effect now that the Kimberley Process had allowed the diamonds into the global marketplace.
Last week, the Kimberley Process lifted a nine-month ban, enabling Zimbabwe to hold an auction for some 900,000 carats of diamonds.
Several rights groups say abuses at Marange continue. They note the Kimberley Process, which was founded to stop the trading of gems to finance war, does not have a mandate to ban diamonds involved in human rights violations unrelated to armed conflicts.
The Kimberley Process halted the sale of diamonds from the Marange fields late last year after rights groups reported the abuses by the military and said soldiers were smuggling gems out of the country.
Some information for this report was provided by AP.