Higher energy prices pushed the U.S. Consumer Price Index (CPI) up 0.6 percent in September for the second month in a row, the Labor Department reported Tuesday. The report said energy prices jumped 4.5 percent and gasoline prices surged 7.0 percent, while electricity prices edged up 0.2 percent. Food costs also increased 0.1 percent. Excluding the volatile food and energy categories, the so-called \"core\" index rose 0.1 percent in September for the third straight month. Economists monitor core prices to get a sense of broader inflation trends, a key barometer for monetary policy decision-making by the Federal Reserve.