Rates on 30-year fixed-rate mortgages climbed back toward 5 percent this week, following long-term bond yields up on uncertainty over the economy and massive government borrowing.

The 30-year fixed-rate mortgage (FRM) averaged 4.91 percent with an average 0.7 point for the week ending May 28, up from 4.82 percent last week, but well below the 6.08 percent average rate a year ago, Freddie Mac said in releasing the results of its weekly Primary Mortgage Market Survey.

"Fixed-rate mortgage rates followed long-term bond yields higher this week as financial markets try to discern the state of the economy," said Freddie Mac Chief Economist Frank Nothaft in a statement.

The 15-year FRM this week averaged 4.53 percent with an average 0.7 point, up from 4.5 percent last week but down from 5.66 percent a year ago.

Five-year Treasury-indexed hybrid adjustable-rate mortgages (ARMs) averaged 4.82 percent with an average 0.6 point, up from 4.79 percent last week but down from 5.62 percent a year ago.

One-year Treasury-indexed ARMs averaged 4.69 percent this week with an average 0.6 point, down from 4.82 percent last week and 5.22 percent a year ago. The 1-year ARM has not been lower since the week ending Sept. 29, 2005, when it averaged 4.68 percent, Freddie Mac said.