Grain markets catapulted even higher as Russia’s attack on Ukraine put a vital source of global supplies at risk. 

Wheat and corn futures in Chicago both surged by the maximum allowed by the exchange and have been locked there for most of the trading session. Milling wheat traded in Paris soared as much as 16% to a record, and oilseeds also bounded higher—heightening concerns of a further acceleration in global food inflation. 

Russia launched a barrage of missile, artillery and air attacks early Thursday, triggering the worst security crisis Europe has witnessed in decades. Ukrainian sea ports closed, according to the presidential office, throwing commodity exports into chaos. Top wheat buyer Egypt, which mostly gets supplies from the Black Sea area, was forced to cancel its latest tender to import the grain.

“The more this goes on, the more risk premium you need,” Michael Magdovitz, a senior analyst at Rabobank in London, said by phone.

The conflict leaves major crop importers particularly vulnerable, with Ukraine and Russia supplying a vast array of countries spanning Asia to the Middle East to Africa. On Thursday, Egypt canceled its wheat tender after drawing a lone offer—of French grain. It had been flooded with participants in another tender just a week earlier. 

Ukraine still has about 6 million tons of wheat and 15 million tons of corn left to ship this season, Magdovitz said. While buyers can turn to other origins like the U.S. and European Union, its role in the market is “irreplaceable,” he said. 

In addition to the crisis, drought in South America has dimmed the outlook for soybean supplies, sending futures to a nine-year high. Palm oil, which is used in thousands of products from cookies to shampoo, is on a record-breaking run as a labor shortage crimps output in major producer Malaysia.

That could feed through to higher prices at grocery stores as everything from pasta to chocolate becomes more expensive to produce, further squeezing household budgets. A measure of global food costs calculated by the United Nations approached a record in January.

Ukraine and Russia account for more than a quarter of the global trade in wheat and about a fifth of corn sales and 80% of sunflower oil exports. 

Wheat in Chicago was 5.7% higher at $9.3475 a bushel at 7:28 a.m. local time, locked up by the 50-cent maximum move versus the prior close. Corn was also about 5% higher and palm oil in Malaysia also spiked.

Exacerbating the inflation outlook is the surging cost of fertilizer. The market is already feeling the pinch due to reduced potash supplies from Belarus after U.S. sanctions, and any reduction of crop-nutrient exports from Russia will fuel the squeeze. Farmers scaling back use of the minerals may trigger lower crop yields, adding to supply concerns. 

There are signs that China, the world’s top importer of agricultural products, is concerned about the rally. Beijing announced this week that it would sell edible oil and soybeans from state reserves to boost supply on the domestic market. The Dalian exchange will also raise margin requirements for some corn and soybean meal futures contracts in a bid to cool speculation.

“Thursday’s rally in agricultural commodities is purely triggered by the Russia-Ukraine conflict,” said Gnanasekar Thiagarajan, head of trading and hedging strategies at Kaleesuwari Intercontinental. “Prices could jump further before witnessing a sharp correction in the coming weeks.”