The wave of misery caused by America' sub-prime mortgage crisis engulfed more homeowners in April as foreclosures rose by 65% year-on-year, adding to pressure on the White House to provide relief for stricken borrowers. Banks filed foreclosure papers on 243,353 US properties last month according to RealtyTrac, an online marketplace for repossessed homes. The figure was up 4% on March and experts suggested that the rate of increase would be higher were it not for a logjam at courtrooms, with over-burdened clerks taking several months to process paperwork.