The average long-term U.S. mortgage rate rose again this week, reflecting ongoing bond market jitters over the war with Iran.

The benchmark 30-year fixed rate mortgage rate ticked up to 6.11% from 6% last week, mortgage buyer Freddie Mac said Thursday. One year ago, the rate averaged 6.65%.

The average rate is now back to where it was five weeks ago. Just two weeks ago, it touched its lowest level in three and a half years. It has been hovering around 6% this year, an encouraging backdrop for prospective home shoppers who can afford to buy at current rates just as the spring homebuying season gets rolling.

Meanwhile, borrowing costs on 15-year fixed-rate mortgages, popular with homeowners refinancing their home loans, also rose this week. That average rate rose to 5.5% from 5.43% last week. A year ago, it was at 5.8%, Freddie Mac said.

Mortgage rates are influenced by several factors, from the Federal Reserve’s interest rate policy decisions to bond market investors’ expectations for the economy and inflation. They generally follow the trajectory of the 10-year Treasury yield, which lenders use as a guide to pricing home loans.

The 10-year Treasury yield was at 4.25% at midday Thursday, up from around 4.13% a week ago.

Treasury yields have climbed recently as rising oil prices have stoked fears of higher inflation. That concern has outwestighed last month’s surprisingly weak report on hiring by U.S. employers and a relatively stable snapshot on inflation at the consumer level taken before the outbreak of the Iran war.

“Under normal circumstances, these soft economic readings would put downward pressure on mortgage rates, however, the news out of the Middle East is overriding those signals,” Hannah Jones, senior economist research analyst at Realtor.com said in an email.

Higher oil prices can put upward pressure on inflation, which could keep the Federal Reserve from cutting interest rates.

The central bank doesn’t set mortgage rates, but its decisions to raise or lower its short-term rate are watched closely by bond investors and can ultimately affect the yield on 10-year Treasurys that influence mortgage rates.

The U.S. housing market remains in a slump dating back to 2022, when mortgage rates began to climb from pandemic-era lows.

Sales of previously occupied U.S. homes have been hovering close to a 4-million annual pace now going back to 2023 — well short of the 5.2-million annual pace that’s historically been the norm. They sank last year to a 30-year low and and have remained sluggish so far this year, falling short of their year-earlier pace in January and February even as mortgage rates are lower than they were a year ago.