The most-traded iron-ore contract for September delivery on China's Dalian Commodity Exchange ended daytime trading 5.2% lower at 1,064 yuan ($165.46) a tonne, after earlier hitting 1,016 yuan, its weakest since April 15.
Dalian iron-ore has plunged more than 20% since hitting a record high of 1,358 yuan on May 12, when tougher environmental restrictions on steel output in top producer China drove a rally in steel prices.
The most-liquid June contract for the steelmaking ingredient on the Singapore Exchange tumbled as much as 7.5% to $177.35 a tonne, its lowest since April 30.
The National Development and Reform Commission, China's top economic planner, along with other government agencies urged major domestic commodity companies not to drive up prices in a meeting on Sunday.
The talks followed a statement from China's cabinet on Wednesday that the government would manage "unreasonable" price increases for copper, coal, steel, and iron-ore.
