The number of Americans seeking unemployment aid rose last week, though the job market has been improving the past few months.

Applications last week increased by 16,000 to a seasonally adjusted 357,000, the Labor Department reported Thursday. The four-week average, a less volatile measure, rose to 343,000, not much more than the five-year low of 340,750 reported the previous week. Claims are a proxy for layoffs, and they’ve come down steadily since November.