CNN  — 

First-time applications for unemployment benefits rose more than expected last week, indicating that cracks may be forming in America’s long-solid labor market.

There were an estimated 242,000 jobless claims filed last week, according to seasonally adjusted data released Thursday by the Department of Labor. That’s an increase of 22,000 from the prior week’s tally and a figure that landed well above economists’ expectations for 220,000 claims.

It’s the largest weekly spike in claims in more than four months and the weekly claims — a proxy for layoffs — are at their highest level since early December, Labor Department data shows.

However, it’s not yet known to what extent the widespread layoffs occurring within the US government are having an effect.

“Do not expect a bursting of the pipes in initial claims and unemployment yet,” Joe Brusuelas, principal and chief economist at RSM US, said Thursday. “For now, it’s more likely to be a steady drip, drip, drip in the pace of firings.”

Initial claims data, in part because of its timeliness, can be quite volatile from week to week and is frequently revised.

Thursday’s report did show that there were an increasing number of first-time claims filed in Washington, DC; however, filings in Maryland and Virginia did not increase for the week ended February 22.

Federal worker-specific unemployment data is lagged by a week, and did not indicate a meaningful jump from the week before.

This story is developing and will be updated.