The unusual trade flow offers another sign that consumers in Europe are running critically short of one of the world’s most widely used industrial commodities. Once-plentiful stockpiles around the world have shrunk dramatically and exchange inventories are at record lows in Europe, while production in the region has dropped after surging power costs reduced smelting profits.

“If I was a trader I’d be looking to move material into Europe at the current time,” Colin Hamilton, managing director for commodities research at BMO Capital Markets, said by phone from London. “I think we’ll see Port Klang empty a bit.”

Tight supplies meant prices were rising even before tensions over Ukraine added to uncertainty. Russia’s exports equate to about 4% of global production, and the risk that shipments could be throttled by potential sanctions is adding fuel to the rally. Aluminum surged to $3,380 a ton on Tuesday, just short of a record high.

Read: Could Aluminum Stockpiles Disappear by 2024? Trafigura Thinks So

Many analysts and traders say it’s unlikely policymakers will target Russia’s aluminum industry directly, particularly after U.S. sanctions against United Co. Rusal International PJSC sparked turmoil in the aluminum market in 2018. But there’s still a risk that sanctions against Russia’s financial institutions could disrupt aluminum shipments, while a reduction in gas exports would cause major problems for European producers who are already struggling with surging power costs.

“At this time I don’t expect we’ll see sanctions that would roil the market, simply because of the lessons learned in 2018,” Mark Hansen, CEO of London-based trading house Concord Resources Ltd., said by phone. “That being said, this is a serious and fast-moving situation.”

With demand booming, any further supply disruptions would be a big blow to manufacturers who are already paying steep prices to get hold of spot metal. Aluminum is used in all kinds of everyday items, from beer cans to iPhones and cars, so the impact is widely felt.

For now, as the largest storage point for aluminum in the London Metal Exchange’s global network, Port Klang is providing an unlikely lifeline for consumers around the world as reserves run dry. That’s a sharp role reversal for the warehouses that for years served as a dumping ground for the industry’s surplus metal.

Still, the shipments from Malaysia may not provide much lasting relief. The profitability of shipping metal across long distances can quickly wilt, and logistical bottlenecks mean aluminum is leaving the port at a sluggish pace, the two traders involved in the transactions said.

The next bulk vessel shipping out from Port Klang won’t be available until June, the traders said, asking not to be named due to the commercial sensitivity of the trades. There are also large queues to withdraw metal from exchange warehouses in the port.

Financing the shipments is also becoming problematic as spot aluminum prices trade above futures on the LME, in a condition known as backwardation that could lead to hedging losses while the cargos are in transit.

Read: From Aluminum to Zinc, Key Metals Are All Flashing Tight Supply

With the backwardation rising, traders who are waiting to withdraw metal from LME warehouses in the port may instead decide to deliver it back in, the traders said.

Beyond the short-term relief that the stash in Port Klang might provide, the broader question for consumers and traders is how the deepening shortages will be solved over the longer term.

Traders and banks including Trafigura Group and Goldman Sachs Group Inc. have warned that further price spikes may be needed to incentivise new supply. But with surging raw material prices piling pressure on manufacturers, it’s also possible the global shortages will end up being alleviated by a slump in demand — creating risks for investors and physical traders alike.

“Because of the backwardation, I think every ton that can move to satisfy that demand has moved already,” Concord’s Hansen said. “At the same time, it’s also very difficult to look at prices and premiums today and say this looks attractive from a risk-reward perspective.”