The Labor Department reported 386,000 initial jobless claims were filed in the week ending July 14, an almost 10 percent increase from the prior week's upwardly revised figure.

The increase was well above expectations of a rise to 365,000 jobless claims.

"Although the deterioration should be cautiously interpreted, as the Labor Department pointed to difficulty with seasonal factors due to changing timing of annual auto plant layoffs, the outsized increase is nonetheless disheartening," said Sara Kline at Moody's Analytics.

The overall trend in claims, which signal the pace of layoffs, has been downward in recent months.

The four-week moving average, which helps to smooth week-over-week volatility, fell by 1,500 to 375,500 last week.

In two days of congressional testimony this week, Federal Reserve Chairman Ben Bernanke pointed to a gloomy outlook for the US economy, warning further drops in unemployment would likely prove "frustratingly slow."

With unemployment stuck above eight percent -- where it has been for more than three years -- Bernanke expressed the Fed's willingness to act if necessary, but gave no hints about concrete action.

The United States added a meager 80,000 jobs in June, the third month of weak jobs growth. The unemployment rate was unchanged at 8.2 percent from May.