London CNN  — 

Wheat prices rose sharply Monday following a strike by a Russian drone on a Ukrainian port on the Danube river.

Moscow’s drones attacked Ukraine’s port infrastructure overnight, targeting the country’s grain stocks, the Ukrainian Army said. One grain silo at the Reni port was hit and substantially damaged, according to geolocated images and video.

Wheat futures on the Chicago Board of Trade jumped 8.5% to $7.57 a bushel, and corn futures rose 4.7% to $5.52 a bushel.

Traders are concerned about tightening supply following the collapse of the Black Sea grain deal last week and a string of Russian drone attacks on Ukrainian port infrastructure.

The deal — originally brokered by Turkey and the United Nations a year ago — had ensured the safe passage of ships carrying grain from Ukrainian ports. So far the pact has allowed for the export of almost 33 million metric tons of food through Ukrainian ports, according to UN data.

Ukraine Operational Command South
Russian drones attacked Ukraine's port infrastructure on the Danube river overnight.

Before the war, Ukraine was the fifth-largest wheat exporter globally, accounting for 10% of exports, according to the Organization for Economic Cooperation and Development.

The White House said the Black Sea deal had been “critical” to bringing down food prices around the globe, which spiked after Russia invaded Ukraine in February last year.

The global food price index compiled by the UN’s Food and Agriculture Organization hit an all-time high in March 2022, but has fallen steadily since then.

Romanian President Klaus Iohannis said in a tweet Monday that the attacks on the ports in the Danube posed “serious risks to the security in the Black Sea,” adding that it would affect Ukrainian “grain transit [and] thus the global food security.”

— Clare Sebastian, Maria Kostenko and Martin Goillandeau contributed reporting.