U.S. home prices jumped 12.2 percent in May compared with a year ago, the biggest annual gain since March 2006. The increase shows the housing recovery is strengthening.

The Standard & Poor's/Case-Shiller 20-city home price index released Tuesday also surged 2.4 percent in May from April. The month-over-month gain nearly matched the 2.6 percent increase in April from March — the highest on record.

The price increases were widespread. All 20 cities showed gains in May from April and compared with a year ago.

Prices in Dallas and Denver reached the highest level on records dating back to 2000. That marks the first time since the housing bust that any city has reached an all-time high.

Home values are rising as more people are bidding on a scarce supply of houses for sale. Steady price increases, along with stable job gains and historically low mortgage rates, have in turn encouraged more Americans to buy homes. One concern is that higher mortgage rates could slow home sales. But many economists say rates remain low by historical standards.

Associated Press