Construction's unemployment rate continued to decline in May compared with April's level and the year-earlier rate as the industry added 17,000 jobs, the federal Bureau of Labor Statistics has reported.

BLS, in a report released on June 5, said that construction's May jobless rate fell to 6.7% from April's 7.5%. It also was a steep drop from May 2014's level of 8.6%.

Last month's rate was the lowest for May since 2006, when it was 6.6%. The BLS unemployment rates aren't adjusted for seasonal variations.

All construction segments gained jobs in May, led by specialty trade contractors, which picked up 12,300.

Buildings construction expanded by 4,400 jobs. Heavy and civil construction added just 400, BLS reported.

BLS statistics show that construction gained 273,000 jobs in the 12 months ended May 31.

Ken Simonson, Associated General Contractors of America chief economist, said, "Right now the two most likely obstacles to the industry's continued expansion are growing labor shortages and politicial gridlock that could curtail public-sector investments in infrastructure and construction."

At the Associated Builders and Contractors, which focuses on nonresidential construction, Chief Economist Anirban Basu said that sector added 8,200 jobs in May. He termed the increase "solid, but unremarkable."

Basu added, "While some would interpret that as due to a lack of increase in demand for human capital, recent sharp increases in industry wage rates suggest that construction firms are experiencing greater difficulty locating and securing properly skilled and credentialed workers."

The overall national unemployment rate edged up to 5.5% in May, from April's 5.4%, despite a gain of 280,000 jobs during the month. The February and March rates also were 5.5%.

Story corrected on June 9 to correct BLS release date, editing error.