The September iron ore contract was traded around 880 yuan a tonne in morning session.
While China has not relaxed steel production curbs as yet, mills are not supported to increase inventories in the short term and that could affect price gain in a far-month contract, SinoSteel Futures added.
Benchmark iron ore futures on the Dalian Commodity Exchange , for January delivery, was down 8.1% at 763 yuan ($118.07) per tonne, as of 0255 GMT, the biggest percentage loss since July 30.
The most-traded September Singapore iron ore contract also slumped, down 6.1% to $143 a tonne.
Steel prices on the Shanghai Futures Exchange were also undermined by a drop in raw materials and tepid economic data.
China’s factory activity slipped into contraction in August for the first time in nearly 1-1/2 years as covid-19 containment measures, supply bottlenecks and high raw material prices weighed on output in a blow to the economy.
(With files from Reuters)
