Unrest in the Ukraine pushed up prices for corn and wheat Tuesday.
Corn rose 8 cents, or 1.7 percent, to settle at $5.02 a bushel. Wheat rose 4 cents, or 0.6 percent, to $6.80 a bushel.
Ukraine's acting president ordered security forces to resume operations in the country's east Tuesday after the bodies of two people allegedly abducted by pro-Russia insurgents were found and a military aircraft was reportedly hit by gunfire.
The twin developments stoked concerns that last week's international agreement on easing Ukraine's crisis was failing.
Ongoing tensions between Ukraine and Russia have rattled wheat prices this year. Ukraine supplies 6 percent of the world's wheat export market, according to U.S. Wheat Associates, a trade group.
In other trading, soybeans slipped 17 cents to settle at $14.71 a bushel.
Metal prices were mixed. Gold for June delivery fell $7.40 to settle at $1,281.10 an ounce. Silver for May rose a penny to $19.36 an ounce.
Copper for May also rose a penny to $3.05 a pound. Platinum for July slipped 40 cents to $1,400.30 an ounce, while palladium for June gained $5.85 to $783.65 an ounce.
In the market for oil and gas, crude oil fell $2.24 to settle at $102.13 a barrel.
In other energy futures trading on the Nymex:
— Wholesale gasoline for May delivery was flat at $3.10 a gallon.
— May heating oil lost 1 cent to $3 a gallon.
— Natural gas for May rose 4 cents to $4.74 per thousand cubic feet.