Myanmar has released seven aid workers detained since June for alleged involvement in sectarian violence in the western sate of Rakhine, sources confirmed Saturday. The chairman of Sittwe Rakhine National Development Party, said four local members of the Dutch non-governmental organization Arsten Zonder Grenzen had been released along with three staff members of United Nations organizations. "Two of our staff were released," said Vivian Tan, spokeswoman for UN High Commissioner for Refugees (UNHCR) Bangkok office. "No details were given about the reason for their release." It was unclear which UN agency the third person was from. Three UNHCR staff were detained in June on charges of siding with Muslim Rohingyas in a sectarian fighting between Buddhist and Muslim communities that left at least 77 people dead. UN special envoy Tomas Ojea Quintana, who visited Rakhine state earlier this month, said the charges against the UN staff were groundless and demanded their immediate release. He called on Myanmar to allow an independent investigation of the violence, which has raised concern about the government's commitment to human rights at a time it has won international praise for pushing through dramatic political and economic reforms. Earlier Friday, President Thein Sein announced an investigation to be led by Myo Myint, retired director of the Religious Affairs Ministry and Kyaw Yin Hlaing of the Myanmar Egress non-governmental organization. The 27-member commission will also include well-known comedian Zagana, student activist leader Ko Ko Gyi, representatives from several political parties and leaders of Christian and Muslim groups. The Rohingya Muslim minority has been a target of abuse since 1982, when the governmet classified them as stateless Bengalis who had migrated to Myanmar in the 1800s and 1900s when the country was under British colonial rule.