Wheat prices have climbed in recent weeks after attacks on grain ships and port infrastructure in the Black Sea and the Sea of Azov by both Ukraine and Russia.
The Russian Defence Ministry said on Wednesday its forces attacked Ukrainian ports and military infrastructure in the Odesa region.
The ministry said two naval vessels had been hit as a result of the strikes, as well as port infrastructure facilities used for unloading and storing military cargo and fuel and lubricant storage tanks in the port of Odesa.
"There is no direct link with grains, but any sign of disturbance in Odesa is supportive," a French trader said.
A Russian missile strike on a ship carrying corn near Ukraine's southern port of Odesa killed 10 people, Ukrainian officials said on Monday, in the deadliest attack in a weeks-long flare-up of violence in the Black Sea.
The greater Odesa hub handles over 90% of Russia's grain and vegetable oil shipments.
Expectations of lower output are also supporting wheat prices after crop scouts on the first day of an annual three-day tour of North Dakota's hard red spring wheat crop projected an average yield in the southern portion of the state at 46.0 bushels per acre (bpa) on Tuesday evening. That figure was 8% below the estimate for the same area last year and just above the five-year average of 45.8 bpa.