U.S. consumer prices jumped in April by the largest amount in more than three years, reflecting a surge in the price of gasoline and other energy products. But outside of volatile food and energy, core inflation posted another modest gain.

The Labor Department says overall consumer prices rose 0.4 percent in April after a 0.1 percent increase in March. It was the largest one-month advance since a 0.6 percent increase in February 2013. Core inflation was up 0.2 percent compared to a 0.1 percent March gain.

Over the past 12 months, overall inflation is up 1.1 percent while core prices have risen 2.1 percent, both considered modest gains. The fact that inflation has remained low has given the Federal Reserve the flexibility to keep interest rates at ultra-low levels.