Chinese steel futures closed at all-time highs on Monday, underpinned by robust demand and concerns over production curbs, while benchmark iron ore prices hit record highs, fuelled by structural supply shortage.

The northwest Shaanxi province recently urged local departments, as requested by China's state planner and other authorities, to verify local steelmakers' crude steel output in 2020 and explain those whose production exceeded designated capacity or didn't meet it.

Another major steelmaking city Handan in the Hebei province recently issued a notice, asking mills to implement production-control measures in the second quarter.

The measures have sparked concerns of more curbs in the ferrous sector, lifting prices as demand is still strong during the peak season.

The most-active construction rebar on the Shanghai Futures Exchange, for October delivery, rose as much as 4.3% to 5,475 yuan ($843.63) a tonne. It closed up 2.3% at 5,371 yuan.

Hot-rolled coils, used in cars and home appliances, ended up 3.2% at 5,737 yuan per tonne, after rising as high as 5,795 yuan earlier in the session.

The sky-rocketing steel prices also underpinned steelmaking ingredients.

Iron ore futures on the Dalian Commodity Exchange, for September delivery, closed 4.3% higher at 1,145 yuan. The contract jumped 6.3% earlier.

"Iron ore prices are mainly supported by structural contradiction of supplies, there's shortage in medium and high-grade products," said Zhuo Guiqiu, analyst with Jinrui Capital.

Even the low-grade Super Special Fines with 56.7% iron content is at over 1,200 yuan a tonne, which is more expensive than the most-traded futures contract, Zhuo added.

Spot prices for 62% iron ore rose $0.5 to $187.5 a tonne on Friday, according to SteelHome consultancy.

Dalian coking coal increased 2.3% to 1,789 yuan and coke up 2.9% at 2,679 yuan a tonne.

Shanghai stainless steel, for June delivery, rose 1.9% to 14 190 yuan per tonne.