US consumer prices jumped 0.4 percent in February driven by the sharp rise in gasoline costs, the Labor Department said Friday. The pickup in inflation was double the rate of January, but the department noted that stripped of the more volatile food and energy prices, the \"core\" rate -- watched by Federal Reserve for interest rate decisions -- rose just 0.1 percent, slower than January. \"The gasoline index rose sharply in February, accounting for over 80 percent of the change in the all items index,\" the department said. \"The gasoline increase led to a 3.2 percent rise in the energy index despite a decline in the index for natural gas.\"