WASHINGTON – Average long-term U.S. mortgage rates rose this week for only the second time this year.

It was the second straight weekly increase for long-term loan rates, which had declined since the start of the year amid global economic anxiety and market turbulence. Rates still remain at historically low levels at the start of the spring home buying season.

Mortgage buyer Freddie Mac says the average rate on a 30-year, fixed-rate mortgage edged up to 3.68 percent from 3.64 percent last week. The benchmark rate remains below the 3.86 percent level it marked a year ago.

The average rate on 15-year fixed-rate mortgages increased to 2.96 percent from 2.94 percent last week.