Last week’s jobless claims shot up four times higher than analysts expected, a sign that a downturn in housing and the credit crisis may be affecting the labor market, the Associated Press reported.

According to the Labor Department, the number of newly laid-off workers filing claims for unemployment benefits reached 337,000 last week, 28,000 more than the previous week. It was the largest jump since Feb. 10 and the highest number since Aug. 25. Economists had expected a 6,000 increase in initial claims.

Government analysts attributed part of the rise to changes at the start of a new quarter, when companies tend to adjust for the season.

The four-week average for claims reached 316,500, the highest level in four weeks.