Guinea's National Electoral Commission has approved the hiring of South African software firm Waymark to compile a new list of registered voters for elections on May 12.

The 11 opposition supporters on the 25-member commission objected to the decision Friday, charging that Waymark was open to voting fraud because it was selected by the ruling party.

The controversy over Waymark is the center of electoral tensions. Thousands of opposition supporters marched in Guinea's capital, Conakry, to protest Waymark in September. Police dispersed the demonstration with tear gas.

Guinea's opposition spokesman Abou Sylla Bacar said Friday another march against Waymark is planned for next week.

In a separate development, the governor of Conakry, Sekou Resco Camara, was charged with committing torture in 2010, according to the International Federation for Human Rights.