Job seekers stand in a line at a career fair in Chicago.

The number of Americans filing for unemployment benefits unexpectedly fell last week, pointing to sustained labor market strength even as the pace of job growth is slowing.

Initial claims for state unemployment benefits decreased 4,000 to a seasonally adjusted 259,000 for the week ended Sept. 3, the lowest level since mid-July, the Labor Department said on Thursday. Claims for the prior week were unrevised.