After falling to their lowest level in almost three years, first-time claims for unemployment benefits increased by 26,000 to 397,000 in the week that ended March 5, the Labor Department announced on Thursday. Although this was only the second increase in six weeks, it was higher than economists forecast. Bloomberg News quoted a Labor Department official who said that “claims generally rise the week after a federal holiday and some New England states reported more claims due to school holidays. Presidents’ Day was Feb. 21.” The four-week moving average, a less volatile number was 393,250, an increase of 3,000 from the previous week.The Labor Department also reported that for the week that ended Feb. 26 the number of people continuing to collect jobless benefits was nearly 3,771,000, a decrease of 20,000 from the preceding week. The seasonally adjusted unemployment rate for those eligible for benefits was unchanged at 3%.