NEW IRAQ AGENCY TO HUNT REBELS
Iraqi authorities, with help of US intelligence agencies, are creating intelligence service that will focus on rooting out guerrilla fighters, especially those from outside country; service will employ some former agents of Saddam Hussein's security apparatus and will probably receive financing from US; it will employ 500 to 2,000 people, and is expected to be formed before Bush administration transfers sovereignty to Iraqi government on June 30; CIA is taking lead in helping put together new service; photo shows partly destroyed headquarters of Saddam Hussein's secret police (M)