Coking coal prices in China saw a near 6% increase, while coke jumped upward of 4%, as concerns about tighter supply amid longer production curbs grew following the return of investors from a weeklong holiday, Reuters reported Oct. 8.

A winter output production plan by the city of Handan in the Hebei province detailed that restrictions on heavy industries will run from Nov. 1 until March 31, 2019, which is a month longer than last winter.

January coke futures saw a 4.2% increase, coming to 2,331.50 yuan per tonne, which was also driven by worries of limited supplies in the Shanxi province.

"The price hike in the spot market also supported futures, with coking coal prices for long-term contracts rising 70-100 yuan a tonne at some producers," a Shandong-based trader told Reuters. The environmental ministry of China previously told heavy industrial companies to comply with emission rules despite Beijing's move allowing provinces to set their own output restrictions.

As of Oct. 8, US$1 was equivalent to 6.93 Chinese yuan.