A group that helped set up a program to prevent the retail sale of \"blood diamonds\" says it left the program to protest sales of diamonds from Zimbabwe. Global Witness pulled out of the Kimberley Process diamond-certification program, established in 2003 to prevent sales of rough diamonds in African war zones, the Los Angeles Times reported Monday. So-called blood diamonds, also referred to by various other names, including \"war diamonds,\" are used to finance insurgencies and wars. \"Nearly nine years after the Kimberley Process was launched, the sad truth is that most consumers still cannot be sure where their diamonds come from, nor whether they are financing armed violence or abusive regimes,\" Charmian Gooch, a founder of London-based Global Witness, said in a statement. \"It has become an accomplice to diamond laundering -- whereby dirty diamonds are mixed in with clean gems.\" Zimbabwe has been accused of human rights abuses in one of its biggest diamond fields, the Marange deposit. The Times said several other advocacy groups were reviewing whether to continue to support the Kimberley Process, embraced by 75 countries. The United Nations created the certification system after insurgents in Angola, Sierra Leone and Liberia sold rough diamonds on global markets to finance their wars. Sales of diamonds acquired through other forms of violence also should be forbidden, human rights groups say, pointing to the Marange fields. In 2008, rights groups say, troops loyal to President Robert Mugabe\'s ruling ZANU-PF party seized the Marange fields, allegedly by killing hundreds of prospectors and forcing others into servitude. U.S. sanctions are designed to prevent the import of Marange diamonds. But experts say the diamonds may be cut, polished and traded in different countries to hide their origin, making enforcement difficult.