The number of Americans applying for first-time unemployment benefits rose last week to 343,000, an increase of 7,000 and also higher than the number that analysts were expecting, the Labor Department said Thursday.

Economists caution against reading too much into often-volatile July data, due to the auto plant retoolings/shutdowns and end-of-school claims that typically occur in the month.

Analysts polled by expected, on average, initial claims for the seven days between July 14 and July 20 to rise but to only 340,000, above the previous week's revised figure of 336,000. By comparison, there were 363,000 first-time claims filed during the comparable week last year (seasonally adjusted).

For the seven days ended July 20, the four-week moving average, considered a more-reliable measure of labor market trends, dropped to 345,250, a decrease of 1,250 from the previous week's revised average of 346,500.

"The total number of people claiming benefits in all programs for the week ending July 6 was 4,840,609, an increase of 317,403 from the previous week," the Labor Department said in a statement. "There were 6,034,225 persons claiming benefits in all programs in the comparable week in 2012."