Applications for U.S. home mortgages rose last week as interest rates fell to their lowest level this year, an industry group said on Wednesday.

The Mortgage Bankers Association said its seasonally adjusted index of mortgage application activity, which includes both refinancing and home purchase demand, rose 21.7 percent in the week ended August 5.

The MBA's seasonally adjusted index of refinancing applications rose 30.4 percent to its highest level this year, while the gauge of loan requests for home purchases fell 0.9 percent.

The refinance share of mortgage activity increased to 75.6 percent of total applications from 70.1 percent the previous week.

Fixed 30-year mortgage rates averaged 4.37 percent in the week, down 8 basis points from the week before. (Reporting by Alexandra Alper; Editing by Diane Craft)