China’s main industrial commodities tumbled on Thursday after the government announced stepped-up measures to keep a lid on soaring raw materials prices which threaten to undermine the country’s economic recovery. Prices of key steelmaking ingredients iron ore and coking coal, as well as steel products such as rebar and hot-rolled coil, all dropped more than 5 percent as traders offloaded supplies, and speculators placed short-sided bets that Beijing’s measures will trigger a further pullback in metals markets. China’s cabinet announced on Wednesday that it will strengthen management of commodity supply and demand to curb “unreasonable” prices and investigate behaviour that bids up commodity costs, spooking China’s hoards of metal traders. “Some of the measures could have an immediate impact on the supply demand balance, for example, if the government decides to release some state reserve into the market,” said Yanting Zhou, Wood Mackenzie senior economist. “Other measures will take effect …