The number of Americans initially applying for unemployment aid last week remained unchanged, a sign that the labor market was losing momentum, the US Labor Department reported Thursday.

The advance figure for seasonally adjusted initial claims for jobless benefits was 370,000 in the week ending May 12, and the four-week moving average, which helps smooth out week-to-week volatility, continued to tick down to 375,000, a decrease of 4,750 from the previous week's revised figure.

The number of jobless claims below 375,000 indicated a sustained drop in the unemployment rate. But the surge in applications in the first three weeks of April raised fears that the job market was sputtering after a strong winter.

The advance figure for seasonally adjusted insured unemployment during the week ending May 5 was 3.265 million, up 18,000 from the prior week.

Federal Reserve officials last month affirmed their plan to hold interest rates near zero at least through late 2014 as they seek to push down an unemployment rate that had topped 8 percent for more than three years. The central bank forecast that the jobless rate may fall to 7.8 percent to 8.0 percent by the end of this year.