The number of available jobs in the US grew in August, signaling an undercurrent of strength in the labor market at a time when its vitals are being carefully monitored by the Federal Reserve.

America’s employers added a surprisingly strong 254,000 jobs in September, the latest evidence that the U.S. labor market is still solid enough to support steady hiring and a growing economy.

Last month’s hiring gain was up sharply from the 159,000 jobs that were added in August, and the unemployment dropped from 4.2 percent to 4.1 percent, the Labor Department said Friday.