Markets tumble as Bernanke delivers dollar warning

The Dow Jones opened sharply lower Thursday after US jobless claims hit their highest level in more than three months. Meanwhile, Federal Reserve chairman Ben Bernanke expressed concerns US public debt could hit the dollar. He told the Senate Banking committee the nation's public deficit - projected to reach 11% of GDP by the end of the year - "could impact" interest rates and the dollar. Rates would have to stay low for a lengthy period, he said, to counter the weak job market. The Fed chief urged the US congress and administration to "find a solution" to the rising national d...