Chinese coking coal futures surged almost 6% on Friday, climbing to a three-month peak, after some major coal-producing regions ramped up their safety inspections, stoking supply concerns.
Authorities in provinces and region including Shanxi, Henan and Inner Mongolia have recently stepped up inspection at coal mines following several accidents in the past few months and ordered those with risks to halt production for rectification.
Meanwhile, data from China's National Statistics Bureau showed that overall coal production in March dipped 0.2% from the same month a year earlier to 340.76 million tonnes.
Coking coal inventories at 110 steel mills in China this week fell 1.5% from a week earlier, according to data compiled by Mysteel consultancy.
The most-traded coking coal futures on the Dalian Commodity Exchange, for May delivery, closed up 5.75% at 1,684 yuan ($258.17) a tonne. Earlier in the session, the market climbed to its highest since Jan. 19 at 1,703.5 yuan a tonne.
Coke prices on the Dalian bourse gained 1.4% to 2,472.5 yuan a tonne.
Benchmark iron ore futures, for September delivery, increased 0.9% to 1,046 yuan per tonne.
Spot prices for 62% iron ore rose by $3 to $176.5 a tonne, as of Thursday, from the previous session, data from SteelHome consultancy showed.
The October contracts for Shanghai steel rebar and hot-rolled coil futures edged lower, with rebar falling 0.1% to 5,116 yuan a tonne and hot-rolled coils slipping marginally to 5,413 yuan per tonne.
Stainless steel futures on the Shanghai Futures Exchange rose 0.6% to 13,925 yuan a tonne.
China's crude steel output jumped to the highest in seven months to 94.02 million tonnes in March, fuelled by strong demand and decent profit margins despite environmental curbs in major steel producing areas.