(IDEX Online) - De Beers will slash diamond production by 20 per cent this year, blaming coronavirus and the resulting Indian lockdown, mine closures in South Africa and US slump in demand.It has revised down its 2020 forecast from between 32m and 34m carats to 25m and 27m carats,In an operational update parent company Anglo American says: "At De Beers, lockdown measures have significantly impacted diamond production in southern Africa, manufacturing in India and retail operations in the United States, while consumer demand has returned to the Chinese market. "Production guidance for 2020 has been reduced in line with anticipated demand by c.7 million carats to 25-27 million carats, with lower volumes at all operations."The London-listed miner said that it was aiming to make operating cost savings of of at least $0.5 billion, in addition to about $1.5 billion earnings benefit from both weaker producer currencies and oil prices.Meanwhile Russia's state-owned Alrosa says it still plans to meet its full-year production target for 2020 of 34.3m carats.In March De Beers canceled its third Sight of the year in Gaborone, Botswana, and allowed buyers to defer 100 per cent of their purchases.