Americans filed 320,000 initial jobless claims in the week ending February 28, an increase of 7,000 from the prior week.
The rise in jobless claims, a sign of the pace of layoffs, was stronger than the 295,000 number expected by analysts.
The four-week moving average of new claims rose by 10,250 to 304,750. A year ago the average, which helps to smooth week-over-week volatility, was 337,250.
Claims have trended lower as the labor market tightens with strong jobs growth over the past year.
On Friday, the Labor Department is scheduled to publish its February jobs report. Analysts expected the unemployment rate to have slipped a tenth-point to 5.6 percent, and job growth slowed to a still-solid 240,000 from 257,000 in January.