LONDON—World food prices rose 2.2% in February from the previous month to a record peak, the United Nations' food body said Thursday, as it warned that volatility in oil markets could push prices even higher.

The Food and Agriculture Organization price index rose by 2.2%—the eighth consecutive rise since June—to an average of 236 points last month, the highest record in real and nominal terms since the agency started monitoring prices in 1990.

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