WASHINGTON (MarketWatch) — The number of people seeking unemployment benefits at the end of May remained near a 15-year low, reflecting steady improvement in the labor market amid a flood in hiring over the past 1 1/2 years.

Some 276,000 Americans filed initial jobless claims in the period running from May 24 to May 30, a week that included the Memorial Day holiday. That was down 8,000 from the prior week, the latest figures from the Labor Department show.

The average of new claims over the past month edged up 2,750 to 274,750. The four-week average smooths out sharp fluctuations in the more volatile weekly report and is seen as a more accurate predictor of labor-market trends.

Both jobless claims numbers are still hovering near levels last seen in 2000, reflecting the small number of layoffs taking place in the economy each week.

Although hiring has tapered off since the end of 2014, the economy has still added nearly 200,000 jobs a month through the first four months of this year. And economists predict a 210,000 increase in May when the government on Friday publishes its monthly employment report.

That’s more than enough, economists say, to push the nation’s 5.4% unemployment even lower over time.

Still, nearly 17 million Americans remain unemployed or underemployed, an unusually high number after six years of economic expansion. Companies aren’t hiring as fast as they post job openings, and many complain about a shortage of skilled workers.

This slack in the labor market explains why the Federal Reserve has kept short-term interest rates near zero. The central bank wants to see a further decline in unemployment and evidence of accelerating wage growth before it acts.

Meanwhile, continuing jobless claims declined by 30,000 to 2.19 million in the week ended May 23, the fewest amount since November 2000. These claims reflect people already receiving unemployment checks; in most states they are eligible for 26 weeks of benefits.