Applications for U.S. home mortgages rose last week to their highest level since 2009, 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 18 percent in the week ended June 8.

The MBA's seasonally adjusted index of refinancing applications rose 19.2 percent, while the gauge of loan requests for home purchases, a leading indicator of home sales, rose around 12.8 percent.

"Refinance volume increased as borrowers were able to lock in at mortgage rates below 4 percent, and purchase application volume was its highest level in over six months," said Michael Fratantoni, MBA's vice president of research and economics, in a statement.

The refinance share of total mortgage activity inched up to 79 percent of applications from 78 percent the week before.

Fixed 30-year mortgage rates averaged 3.88 percent in the week, up a single basis point from 3 .87 percent the week before.

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