New applications for U.S. jobless benefits unexpectedly fell last week and the number of Americans on unemployment rolls hit a 28-1/2-year low, pointing to a rapidly tightening labor market that could encourage the Federal Reserve to raise interest rates in June.

Initial claims for state unemployment benefits dropped 2,000 to a seasonally adjusted 236,000 for the week ended May 6, the Labor Department said on Thursday. Claims for the prior week were unrevised.

Economists polled by Reuters had forecast first-time applications for jobless benefits rising to 245,000.