The number of Americans filing applications for unemployment benefits surged to near a 1-1/2-year high last week, which could raise concerns that the labor market is slowing.

CNBC reported initial claims for state unemployment benefits jumped 53,000 to a seasonally adjusted 253,000 for the week ended Jan. 26, the highest level since September 2017, the Labor Department said on Thursday (Jan.31). The rise was also the largest since September 2017.

Claims dropped to 200,000 in the prior week, which was the lowest level since October 1969. Economists polled by Reuters had forecast claims rising to only 215,000 in the latest week.

The claims data covered the Martin Luther King holiday. While claims tend to be volatile around holidays, last week’s big jump could be flagging a moderation in job growth.

The surge could also reflect filings by non-federal government workers who were temporarily unemployed during the partial government shutdown that recently ended. The Labor Department said no states were estimated last week.

The claims data has no bearing on January’s employment report, which is scheduled for release on Friday, as it falls outside the survey period. According to a Reuters survey of economists, nonfarm payrolls likely increased by 165,000 jobs in January after jumping by 312,000 in December.