The US four-week moving average of initial claims for unemployment insurance last week rose by 6,750 to a total of 298,000 from the previous week’s upwardly revised average of 291,250, according to seasonally adjusted numbers released today by the US Department of Labor.

The four-week moving average decreases the volatility of the weekly numbers. Total initial claims for unemployment insurance for the week ended Jan. 10 rose by 19,000 to a total of 316,000 from the previous week’s upwardly revised figure of 297,000.

MarketWatch reports the sharp increase in claims marked their highest level since early September. However, initial claims are prone to sudden swings after the holiday season, so it’s unclear if the increase reflects any deterioration in what’s been a rapidly improving US labor market.

No special factors impacted this week’s initial claims, according to the Department of Labor.