WASHINGTON — Rates on 30-year mortgages have risen for a second straight week, climbing to the highest level in a month.

Freddie Mac, the mortgage company, reported yesterday that 30-year, fixed-rate mortgages averaged 6.10 percent this week, up slightly from 6.09 percent last week. It was the highest level since 30-year mortgages averaged 6.35 percent for the week ending Sept. 4.

Financial markets have been turbulent in recent weeks as demand for safe-haven Treasury securities has pushed those yields down sharply while rates on other types of corporate bonds have been pushed higher by growing concerns about whether the bonds will be repaid.

Those crosscurrents have been reflected in mortgage rates, which also have been on a rollercoaster, hitting a high for the year of 6.63 percent in late July and then dropping below 6 percent in mid-September.

The recent turmoil in credit markets has pushed those rates up from a seven-month low of 5.78 percent on Sept. 18, to above 6 percent for the past two weeks.

Other rates were mixed this week, according to the Freddie Mac survey.

Rates on 15-year fixed-rate mortgages, which are popular with people who are refinancing, edged up to 5.78 percent, compared with 5.77 percent last week.

Rates on five-year adjustable-rate mortgages dipped slightly to 6 percent from 6.02 percent last week. Rates on one-year adjustable-rate mortgages were unchanged at 5.16 percent.