U.S. government debt yields fell on Tuesday as Italian and Spanish political turmoil spooked euro zone markets.
The yield on the benchmark 10-year Treasury note broke below 2.8 percent on Tuesday, down from highs above 3.13 percent earlier this month. The yield on the 30-year Treasury bond, meanwhile, was down at 3.006 percent. Bond yields move inversely to prices.
Concerns about a global credit blight and anemic interest rates appeared to push investors toward safer assets on Tuesday.
Over the weekend, Italy's president appointed former International Monetary Fund official Carlo Cottarelli as interim prime minister to form a new cabinet and restore political order within the country.
The euro zone's third-largest economy has been struggling to establish a stable government since inconclusive elections in March, with anti-establishment forces abandoning their effort to form a ruling coalition over the weekend.