WASHINGTON (AP) — Long-term U.S. mortgage rates jumped this week, reaching their highest levels since late June amid indications of strength in the economy.

Mortgage giant Freddie Mac says the average for a 30-year fixed-rate mortgage rose to 3.54 percent from 3.47 percent last week. Rates remain near historically low levels, however. The benchmark 30-year rate is down from 3.87 percent a year ago. Its all-time low was 3.31 percent in November 2012.

The 15-year fixed-rate mortgage, popular with homeowners who are refinancing, increased to 2.84 percent from 2.78 percent.