Labor markets remain weak, but some hiring activity took place -- particularly for temporary staff, according to the Federal Reserve Beige Book report released Wednesday.

Federal Reserve districts in Cleveland, Richmond VA, Atlanta and Chicago reported strong demand for temporary workers, according to the report.

Staffing firms in the Cleveland District cited increases in job openings, primarily in healthcare. The Dallas District said temporary hiring rose in the high tech, paper and lumber industries.

The Beige Book said overall U.S. economic activity increased since the last report on March 3, except in the St. Louis District, which reported "softened" conditions.