Sierra Leoneans living next to the country’s largest diamond mine are taking their government to West Africa’s regional court for failing to protect them from alleged environmental lapses by the company that runs it, a subsidiary of Octea Limited The complaint, filed to the Economic Community of West African States (Ecowas) court of justice on Thursday, alleges that the government failed to act when residents of Koidu, the largest city in the diamond-rich Kono district, complained about water contamination and damage to their houses from blasting at the mine.