Updated from 8:47 a.m. EST

Consumer prices rose more than expected in January, mostly because of a spike in energy prices, the government said Friday.

The consumer price index was up 0.5%, vs. the consensus economists' forecast of 0.3% and a 0.2% increase in December.

Core prices -- minus food and energy -- rose 0.2%, topping expectations for a 0.1% gain. The core rate rose 0.1% in December.

Energy costs rose 4.7% in January. Food costs were unchanged. Transportation costs were up 1.7%, reflecting higher gasoline prices. The index is up 2% over the past three months and 1.9% over the past 12 months.

Though inflation remains historically tame, the report indicates a gradual pickup is underway.

In a speech earlier today, William Poole, president of the Federal Reserve Bank of St. Louis, offered an optimistic outlook on inflation and economic growth.

"Keeping inflation low and stable depends importantly, though certainly not entirely, on keeping inflation expectations in check," Poole said, "If financial markets, consumers, and producers view this outcome as consistent with the Fed's long-run goals, then I see no reason why we should not see a similarly benign inflation outcome this year."