WASHINGTON - The number of US people initially applying for unemployment aid last week surged due to the effects of superstorm Sandy, the US Labor Department reported Thursday.

The advance figure for seasonally adjusted initial claims for jobless benefits was 439,000 in the week ending Nov 10, up 78,000 from the previous week's revised figure. This is the highest level in 18 months and ends several weeks of declines.

Meanwhile, the four-week moving average, which helps smooth out week-to-week volatility, also increased dramatically to 383,750, breaking a threshold of 375,000.

Jobless claims below 375,000 generally indicates a sustained drop in the unemployment rate. Applications have mostly stayed near that level since the spring, a level consistent with modest job growth.

The advance figure for seasonally adjusted insured unemployment during the week ending Nov 3 was 3.334 million, an increase of 171,000 from the prior week.

The fresh jobless claims data was distorted by the effects of Sandy, which swept the East Coast from North Carolina to Maine, with a large number of applications filed in storm-damaged areas, the department said, adding the effect could last two more weeks.

To boost anemic economic growth and labor market, the US Federal Reserve announced in September it would expand its holdings of mortgage debt until the labor market improved significantly. But the cooling global economy and concerns over a US fiscal cliff is still dampening the employment outlook.