The 26 U.S. cities with the worst foreclosure problems are concentrated in four states – California, Florida, Arizona and Nevada, a report released Wednesday shows.

The report on foreclosures for the first quarter by RealtyTrac Inc. said the highest foreclosure rates were found in Las Vegas, Merced, Calif. and the Cape Coral-Fort Myers area in Florida. Next on the list were the California metro areas of Stockton, Riverside, Modesto, Bakersfield and Vallejo-Fairfield.

Rounding out the top 10 were Phoenix and Port St. Lucie, Fla. Outside of the four high-foreclosure states, the worst foreclosure rates were in Boise City, Idaho (No. 27) and Greeley, Colo. (No. 29).

The number of American households threatened with losing their homes grew 24 percent in the first three months of this year and is poised to rise further as major lenders restart foreclosures after a temporary break.

Nationwide, nearly 804,000 homes received at least one foreclosure-related notice from January through March, up from about 650,000 in the same period a year earlier, RealtyTrac said last week.

The big unknown for the coming months is President Barack Obama’s plan to help up to 9 million borrowers avoid foreclosure through refinanced mortgages or modified loans.

The Obama administration expects it to make a big dent in the foreclosure crisis. But it remains to be seen whether the lending industry will fully embrace the efforts, despite a promise of $75 billion in incentive payments.

(Source: CBS News)