WASHINGTON (AP) — Long-term U.S. mortgage rates rose for the second straight week, continuing to dampen prospects for potential homebuyers.

Mortgage buyer Freddie Mac said Thursday the average rate on 30-year, fixed-rate mortgages jumped to 4.60 percent this week from 4.54 percent last week. Long-term loan rates have been running at their highest levels in seven years. The average benchmark 30-year rate reached a high this year of 4.66 percent on May 24. By contrast, the rate stood at 3.93 percent a year ago.

The average rate on 15-year, fixed-rate loans increased to 4.08 percent this week from 4.02 percent last week.

Higher mortgage rates combined with steadily rising home prices have restrained home sales this summer despite the robust economy and job market.

The Federal Reserve on Wednesday left its key interest rate unchanged but signaled further gradual rate hikes in the months ahead as long as the economy stays healthy.

As prices for U.S. Treasury bonds have dropped, the yield on the benchmark 10-year note rose to 3 percent this week for the first time since mid-June. The rate was at 2.99 percent Thursday morning. Higher yields on Treasurys tend to push interest rates higher on mortgages and other loans.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country between Monday and Wednesday each week.

The average doesn't include extra fees, known as points, which most borrowers must pay to get the lowest rates.

The average fee on 30-year fixed-rate mortgages declined to 0.4 point from 0.5 point last week. The fee on 15-year mortgages was unchanged at 0.4 point.

The average rate for five-year adjustable-rate mortgages rose to 3.93 percent from 3.87 percent last week. The fee dropped to 0.2 point from 0.4 point.