It was said from smelter officials on Monday that the power operator in Henan province has warned local aluminium smelters that its power supplies to the smelters may fall due to local power shortages.

“The power bureau called us on Sunday asking us to prepare for production cuts at our smelter since the local power supply is tightening,” an administration official at a large smelter in Henan told Reuters.

“I can imagine they would call others.”A manager at another large smelter in Henan said the company had received calls from the power operator on Sunday and Monday about warnings of power supply cuts.

Henan, the top primary aluminium producing province in China, has more than 4 million tonnes a year of aluminium smelting capacity.

China is the world’s top producer and consumer of the metal.