Stainless steel was also in the spotlight, with the Shanghai benchmark futures contract tumbling to the lowest level since mid-July on concerns over weak demand that were exacerbated by rising stocks in China.
The most-traded iron ore for May delivery on China's Dalian Commodity Exchange ended daytime trading 3.2% lower at 642.50 yuan ($101.29) a tonne after a three-day advance.
The steelmaking ingredient's most-active January contract on the Singapore Exchange was down 2.5% at $109.70 a tonne by 07:25 GMT.
"The outlook for the iron-ore market is challenging," commodities strategists at ANZ wrote in a note.
"With restrictions on China's steel industry, demand for iron ore is likely to be subdued. Even so, supply constraints combined with a stabilisation in China's property sector should limit the downside."
Earlier this week, China's politburo, its top decision-making body, vowed to promote a healthy development of the property sector, in a statement which came shortly after China's central bank announced a cut in banks' reserve requirement ratio to bolster slowing economic growth.
