China's September coal imports surged 27.5% on the prior year, customs data showed on Friday, as buyers continued to bring in cheaper supplies from abroad ahead of the winter peak season.

Imports came to 42.14 million metric tons, close to August's record 44.3 million tons.

China's recent strong coal imports have been supported by rising domestic coal prices, the result of mine safety inspections following a series of accidents that temporarily tightened supply.

Qinhuangdao free-on-board (FOB) coal , a domestic benchmark, was assessed at $151.68 per ton most recently on Oct. 9, up from a more than two-year low of $116.42 on June 19.

The spot price for 6,000 kilocalories (kcal) coal from Australia’s Newcastle port was assessed at $143.22 per ton on Oct. 9.

Higher industrial usage and seasonal restocking activity ahead of colder weather in northern China also contributed to strong demand for thermal coal.

China's imports during January to September are already up 73.1% compared to the same period of 2022 at 347.65 million tons, the customs data also showed.

Arrivals will likely remain at an elevated level in October and November as demand remains robust, said traders.

A flurry of deals were concluded at the world's largest industry conference in Indonesia last month - the first time for many Chinese buyers to attend an international conference since COVID-19.

"The market is hot, don't expect volume to slow down just yet," said a Beijing-based trader, declining to be identified as he is not permitted to speak to media.

Indonesian imports could fall slightly because of supply constraints, but Australian coal is likely to make up the difference, another trader said. (Reporting by Colleen Howe Editing by Shri Navaratnam and David Evans)