Disappointing jobs reports Wednesday caused traders to buy safer investments such as U.S. Treasurys.
U.S. companies added far fewer jobs in April than in March, according to a private survey by payroll processor ADP. The ADP survey is seen as a harbinger of the government's monthly jobs report, which is due out Friday.
The report added to fears that growth has slowed considerably in recent months as businesses readjusted their pace after an unusually warm winter. Investors see jobs as one key to the economic recovery.
Demand for Treasurys had increased overnight after news that unemployment in the 17 nations that use the euro rose to its highest level since the euro launched in 1999.
The price of the 10-year Treasury note rose 15.6 cents for every $100 invested. That pushed the note's yield down to 1.93 percent as of 3:15 p.m. EDT from 1.95 percent late Tuesday.
The price of the 30-year Treasury bond rose 62.5 cents for every $100 invested, pushing its yield down to 3.12 percent from 3.15 percent late Tuesday.
The yield on the two-year Treasury note was unchanged at 0.27 percent.
The yield on the three-month Treasury bill was unchanged at 0.09 percent.