Investing.com -- US mortgage rates climbed last week by the largest margin since September, marking a setback for a housing market that had benefited from declining financing costs earlier this year.

The contract rate on a 30-year mortgage increased 10 basis points to 6.19% in the week ended March 6, according to Mortgage Bankers Association data released Wednesday. This followed two consecutive weeks of the lowest rates since 2022.

The rise in borrowing costs coincided with a sharp increase in the 10-year US Treasury yield, which is correlated with mortgage rates, as war with Iran disrupted oil flows and raised concerns about inflation.

The MBA's measure of applications for home purchases rose 7.8% last week, the most since early January. An index of refinancing activity edged higher and has increased in all but two weeks this year, based on MBA data.

The market had been showing early signs of momentum as affordability constraints began to ease. Data released Tuesday showed contract closings on previously owned homes climbed in February.

The MBA survey, which has been conducted weekly since 1990, uses responses from mortgage bankers, commercial banks and thrifts. The data cover more than 75% of all retail residential mortgage applications in the US.