NEW YORK: The yield on US 30-year Treasury bonds rose to its highest level since September 2011 in the aftermath of remarks from Federal Reserve Chairman Ben Bernanke who suggested the central bank might reduce its bond purchases later this year if the economy shows further improvement.

The selling in the 30-year or long bond intensified after a poor $7 billion auction of 30-year Treasury Inflation-Protected Securities.

The long bond last traded down 1-30/32 in price with a yield of 3.537 percent, up 11 basis points from late on Wednesday. The 30-year yield touched 3.548 percent earlier, the highest intraday level since early Sept. 2011, according to Reuters data.