The number of Americans filing new claims for unemployment benefits unexpectedly rose last week, but not enough to change views the labor market was strengthening.

Initial claims for state unemployment benefits climbed 4,000 to a seasonally adjusted 317,000 for the week ended June 7, the Labor Department said on Thursday.

The prior week's claims were revised to show 1,000 more applications received than previously reported. Economists polled by Reuters had forecast first-time applications for jobless aid slipping to 310,000 last week.

A Labor Department analyst said there were no special factors influencing the state level data.

The four-week moving average for new claims, considered a better measure of underlying labor market conditions as it irons out week-to-week volatility, increased 4,750 to 315,250.

The economy added 217,000 jobs in May, the fourth straight month of job gains above 200,000. It has recouped all the 8.7 million jobs lost during the recession. The unemployment rate held steady at a 5-1/2 year low of 6.3 percent.

The claims report showed the number of people still receiving benefits after an initial week of aid rose 11,000 to 2.61 million in the week ended May 31.

So-called continuing claims had declined for five straight weeks, an indication that some long-term unemployed were finding work. The unemployment rate for people collecting unemployment benefits has held at 2.0 percent since April.