The number of people applying for unemployment benefits plummeted last week, reversing nearly all the sharp rise reported the previous week.

The number of laid-off workers seeking benefits dropped 44,000 to a seasonally adjusted 434,000, the Labor Department said Thursday. That is the steepest weekly fall since February 2010.

The drop suggests that the increase of 47,000 reported last week was mostly due to temporary factors. The state of New York reported that applications jumped by more than 24,000 two weeks ago, because more school systems had spring break than usual. That led to a spike in temporary layoffs. A new extended benefits program in Oregon had caused applications to rise in that state.

Still, the latest applications figure is far above the 375,000 level typically consistent with sustainable job growth. Weekly applications peaked during the recession at 659,000.

The tornadoes that devastated parts of Alabama led to a jump in applications in that state last week, a department spokesman said, though it wasn't enough to significantly impact the national numbers.

The four-week average of claims, a less volatile measure, rose to 436,750, its fifth straight increase. The average has jumped 46,500, or nearly 12 percent, since early April.

That rise has raised concerns among many economists that hiring could slow this month, weighing on the economy. More jobs are critical to boosting consumer incomes and spending. Consumer spending accounts for about 70 percent of the economy.

Employers have been adding jobs at a healthy pace since February. Companies have added 250,000 jobs each month, on average, in the past three months, the biggest hiring spree in five years. The unemployment rate has dropped nearly a full percentage point in the past five months, though it remains at 9 percent.

The number of people receiving unemployment benefits edged up by 5,000 to 3.8 million, the department said. But that doesn't include millions of additional people receiving emergency benefits under an extended benefits program put in place during the recession. All told, just under 8 million people received unemployment benefits in the week ending April 23, the most recent data available. That's about 30,000 fewer than the previous week.