CHICAGO: US wheat futures surged 6.3% on Monday, supported by concerns about lengthy disruptions to shipments out of Ukraine as fighting intensified in that key grain export country.

The strength in wheat spilled over into the corn market, which was on track to snap a streak of four straight negative sessions, while soybeans were close to unchanged.

Concerns about supplies from the Black Sea region were also heightened by news that Russia had attacked Ukraine’s capital Kyiv for the first time in more than a month.

“The strike undermined the credibility of Russia’s claims that it had no intention of blocking the flow of food-based commodities out of Ukraine’s ports,” Arlan Suderman, chief commodities economist at brokerage StoneX said in a note to clients.

Ukrainian President Volodymyr Zelenskiy said on Monday there could be as much as 75 million tonnes of grain stuck in Ukraine by this autumn and that Kyiv wanted anti-ship weapons that could secure the safe passage of its exports.

At 10:59 a.m. CDT (1659 GMT), CBOT July soft red winter wheat futures were up 57 cents at $10.97 a bushel. CBOT July corn was 15-3/4 cents higher at $7.42-3/4 a bushel.

Dealers noted Russian warships continued to control access to Ukraine’s Black Sea ports with Russian President Vladimir Putin proposing that grain could be shipped via Belarus but only if sanctions against Russia’s ally were lifted.

“Russia is trying to put more pressure on the world to lift sanctions by sabotaging world food supply,” said Ole Houe, director of advisory services at agriculture brokerage IKON Commodities in Sydney.

CBOT July soybeans were up 1/4 cent at $16.98 a bushel.

The US Agriculture Department on Monday morning said that weekly soybean export inspections totalled 350,416 tonnes, down 13.2% from a week earlier and below trade forecasts.