(Bloomberg) — The world’s most crucial metals continued on a breakneck surge, with zinc jumping the most in six years, as energy shortages forced more production cuts, piling pressure on manufacturers and fueling concerns about inflation.

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Producers of metals from zinc to aluminum and steel are restricting output as rising energy costs outpace the spike in metal prices, or because of power restrictions. The latest victim was one of the top zinc producers Glencore Plc, with production at its three European plants being cut because of surging power prices.

Zinc spiked as much as 12% on the London Metal Exchange in response, the biggest increase since October 2015. Aluminum — a particularly energy intensive metal — also gained, taking this year’s advance to 62% this year, while copper extended gains beyond $10,000 a ton. Friday’s gains come after the benchmark index of six base metals on the London Metal Exchange rose to an all-time peak on Thursday.

The supply disruptions come at a crucial juncture for the global economy, threatening to add more strain to creaking supply chains and fanning concerns that inflation risks may linger for longer than previously expected.

“Base metals are rallying amid an intensifying energy crisis, and heightened inflation fears are reigniting investor enthusiasm,” said Wenyu Yao, senior commodities strategist at ING Bank. “Fears of inflation could increase demand for metals as there is a perception that they are a hedge against inflation, which is especially true for copper. In the meantime, a retreat in US real rates, along with the broad trade-weighted dollar index over the last couple of days, is also driving momentum.”

The supply curtailments started in China as the country restricted power to energy intensive industries, and have now spread to Europe as the region faces its own power problems spurred by record gas prices. That’s creating new demand worries as record raw material costs threaten manufacturing sectors around the world.

Industrial and manufacturing companies around the world have cut earnings guidance in recent weeks, while major economies from Germany to the U.K. are growing more slowly then expected.

Glencore’s zinc cuts followed an announcement earlier this week that Nyrstar — another big producer — would reduce output at three European smelters by up to 50% due to rising power prices and costs associated with carbon emissions. Meanwhile, Matalco Inc., the largest U.S. producer of aluminum billet, is warning customers it may curtail output and ration deliveries as soon as next year amid a magnesium shortage. Steelmakers, including ArcelorMittal, have also cut production.

Copper, the most important industrial metal, is also soaring. It’s set for the biggest weekly gain since 2016 and is in a widening backwardation as global inventories shrink due to demand recovery and pandemic-driven disruptions. Rio Tinto Group said Friday that the start up of its Oyu Tolgoi project in Mongolia has been delayed by at least three months after Covid-related restrictions hampered progress.

“As most metals are in backwardation and physical demand high, the ingredients are there for materially higher prices, most notably in aluminium and zinc but also permeating into the copper and tin market,” said Kieron Hodgson, an analyst at Panmure Gordon. “It is increasingly likely these prices may persist throughout the fourth quarter before the inevitable return-to-earth occurs.”

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