(IDEX Online) - Alrosa has resumed operations at its International underground mine, a week after a dozen workers tested positive for COVID-19.The mine (pictured), close to the town of Mirny, in the subarctic Russian republic of Sakha, yields some of the world's highest diamond grades, and produced 2.2 million carats in 2019.All staff have now been tested. Those awaiting results have been furloughed, and those confirmed as negative have returned to work in a two-shift mode designed to keep mine staff separate from contractors working at surface facilities.The state-owned Russian miner says workers diagnosed with coronavirus are being treated at the Mirny hospital and regular tests for the virus among staff will continue.