Chicago Board of Trade (CBOT) wheat and corn futures rose as political strife in Ukraine led to fears of disruption of shipments from the Black Sea, a key grain-exporting zone.

Ukraine is a major exporter of wheat and corn. Wheat futures were up 5.2 percent and corn futures were up 3.8 percent. In Europe, May milling wheat rose 4.6 percent to its highest in nearly three months.

"The market is concerned that the tensions in that part of the world could curb export activity," Luke Mathews, commodities strategist at Commonwealth Bank of Australia, told Reuters. "The importance of the Black Sea region to global grain markets should not be understated."

Ukraine is expected to export 16.8 million metric tons of corn in the 2013-14 season. Analysts and traders said there were no signs yet of trade disruption and that the market was reacting to risks raised by uncertainty caused by growing tensions in the region.

"The market is not reacting to new fundamental factors but is being driven by investment funds that are short and that are reacting to a geopolitical context of uncertainty," Michel Portier, head of grains consultancy Agritel, said in the report.

Others are viewing this uncertainty as an opportunity to capitalize on the instability of the Ukrainian currency.

"I think people are overexcited," one European trader said. "I talked with my corn supplier in Ukraine, this week he will be loading corn to us and today he even bought additional quantities - the price for him is very attractive because of the low exchange rate."