Separately , uncertainty over the future of the Federal Reserve 's stimulus program also dominated markets after a recent string of U.S. economic reports underlined concernsNegative_sentimentover the outlook for the nation 's economic recovery .
ConcernNegative_sentimentthat the Baghdad-controlled Iraqi army was disintegrating and could no longer secure key oil facilities was exacerbated when soldiers fled the northern oil city of Kirkuk , leaving it in the hands of Kurdish forces .