The number of U.S. people initially applying for unemployment aid last week dropped sharply after rising in weeks earlier, signaling labor market recovery is volatile, the U.S. Labor Department reported Thursday.

The advance figure for seasonally adjusted initial claims for jobless benefits was 365,000 in the week ending April 28, a decrease of 27,000 from the previous week's revised figure.

The number of jobless claims below 375,000 indicated a sustained drop in the unemployment rate. Applications moved higher last month after steadily declining since the end of last year.

However, the four-week moving average, which helps smooth out week-to-week volatility, continued to climb to 383,500, the highest level since last December.

Economists point out that the volatility of applications suggests that the U.S. labor market recovery is still fragile.

The advance figure for seasonally adjusted insured unemployment during the week ending April 21 was 3.276 million, down 53,000 from the prior week.

Meanwhile, the job growth also slowed down recently, sparking fresh worries over labor market rebound.

The U.S. private sector only added 119,000 jobs in April, about half of March's figure, according to a report released Wednesday by the Automatic Data Processing, Inc.(ADP).