WASHINGTON — New US claims for jobless benefits dropped to the lowest level since September 2008, government data showed, in a fresh sign of optimism for a weak labor market.

The seasonally adjusted initial claims in the week ending December 19 was 452,000, a decrease of 28,000 from the previous week's unrevised figure of 480,000, the Labor Department said in a report.

It was much lower than the 470,000 figure expected by most economists.

The four-week moving average, a less volatile indicator than the week-to-week figures, fell to 465,250 from the previous week's revised average of 468,000.

The figures suggest the brutal pace of layoffs is easing as the economy pulls out of its worst recession in decades.

The total number of Americans receiving unemployment benefits also fell.

The Labor Department's figures showed the number of seasonally adjusted insured unemployment during the week ending December 12 was 5.076 million, a 127,000 drop from the preceding week's revised level of 5.203 million.

Analysts cautioned that unemployment remained a key problem despite the decline in claims.

"Although the decline in initial and continuing claims is a positive for the labor market, caution should be taken in reading too much into the decline, considering common holiday volatility," said Andrew Gledhill from Moody's Economy.com.

The weekly report offers an up-to-date snapshot of the job market, critical to US economic recovery from recession.

The US labor market witnessed a dramatic improvement in November as the number of jobs lost narrowed to 11,000 and the unemployment rate dipped to 10.0 percent, the government said.

The US economy grew at a 2.2 percent pace in the third quarter, reversing four quarters of contraction.

Yet many economists argue the recovery could be imperiled by high unemployment, limiting consumer incomes and hurting confidence and spending.