BEIJING, Sept 2 (Reuters) - Chinese coking coal futures soared 8% to hit their daily upper limit and an all-time high on Thursday, fuelling a rally in coke prices too, as sluggish imports and production control at mines stoked supply concerns.

Mongolia reported most single-day COVID-19 cases on Sept. 1, indicating imports of coking coal from the country could remain cool this month, Galaxy Futures wrote in a note.

Meanwhile, China's National Mine Safety Administration https://www.chinamine-safety.gov.cn/xw/mkaqjcxw/202108/t20210825_396811.shtml recently reiterated the importance of safety production at mines in the remainder of the year.

Some plants in the Shanxi province had raised coking coal prices, according to a Huatai Futures note, further widening backwardation between spot and futures markets.

The most-active coking coal futures on the Dalian Commodity Exchange, for January delivery, jumped 8% to 2,669 yuan ($412.99) per tonne.

Coke futures on the Dalian bourse also reached trading limit in morning session. They jumped 7.6% to 3,393 yuan a tonne as of 0330 GMT.

Benchmark iron ore futures inched up 0.3% to 781 yuan per tonne, recovering from plunge in previous session.

Spot prices of iron ore with 62% iron content for delivery to China , compiled by SteelHome consultancy, dropped $11 to $147.5 a tonne on Wednesday.

Steel prices on the Shanghai Futures Exchange were mixed.

Construction rebar rose 1.1% to 5,322 yuan a tonne.

Hot rolled coils, used in cars and home appliances, increased 0.8% to 5,567 yuan per tonne.

Stainless steel futures, for October delivery, dipped 0.6% to 17,825 yuan a tonne.

($1 = 6.4627 Chinese yuan renminbi) (Reporting by Min Zhang and Dominique Patton; editing by Uttaresh.V)