(IDEX Online) - Authorities in Angola have seized almost 2,500 diamonds from illegal buyers as part of a long-running crackdown on illicit gem trafficking.They launched Operation Transparency in December 2018, targeting the eastern Lunda Norte province, where there are an estimated 700 illegal mining sites.The country's Criminal Investigation Service (SIC) seized 2,477 diamonds, plus cash equivalent to $36,000, in the town of Cambulo, according to the state-run news agency Angpop.Angola has made repeated efforts to counter diamond smuggling and illegal immigration ,and has faced ongoing allegations over "conflict diamonds".Security forces seized 6,579 diamond stones in 2019, as well as 19 vehicles and $275,000. They also detained almost 150,000 illegal foreign citizens.Angola's currently the world's sixth biggest diamond producer but has yet to explore 60 per cent of its potential kimberlite reserves.