The number of Americans seeking unemployment benefits dropped last week to the lowest level in almost four years, adding to evidence of an improving U.S. labor market.

Initial jobless claims fell 5,000 in the week ended March 24 to 359,000, the lowest since April 2008, the Labor Department reported today in Washington. The median forecast of economists in a Bloomberg News survey called for 350,000 claims. With the report, the government data also contain revisions dating back to 2007.

Companies are retaining workers and hiring as sales pick up along with confidence in the expansion. The pace of employment has gained momentum in the past three months, helping drive income growth that may ease the strain of higher gasoline prices.