Applications for U.S. home mortgages tumbled last week, with demand for refinancing drying up as mortgage rates jumped to their highest level since late June, data from an industry group showed on Wednesday.

The Mortgage Bankers Association said its seasonally adjusted index of mortgage application activity, which includes both refinancing and home purchase demand, fell 7.4 percent in the week ended Aug 17.

The index of refinancing applications lost 9.2 percent, the third week in a row the measure has declined. The gauge of loan requests for home purchases, a leading indicator of home sales, held up better, rising 0.9 percent.

The refinance share of total mortgage activity slipped to 80 percent of applications from 81 percent.

Fixed 30-year mortgage rates jumped 10 basis points to average 3.86 percent. Even with the increase, rates are still at relatively cheap levels after falling to record lows in recent months.

The survey covers over 75 percent of U.S. retail residential mortgage applications, according to MBA.