SEATTLE (AP) -- The U.S. Border Patrol has quietly stopped its controversial practice of routinely searching buses, trains and airports for illegal immigrants at transportation hubs along the northern border and in the nation's interior, preventing agents from using what had long been an effective tool for tracking down people here illegally, The Associated Press has learned.

Current and former Border Patrol agents said field offices around the country began receiving the order last month - soon after the Obama administration announced that to ease an overburdened immigration system, it would allow many illegal immigrants to remain in the country while it focuses on deporting those who have committed crimes.

The routine bus, train and airport checks typically involved agents milling about and questioning people who appeared suspicious, and had long been criticized by immigrant rights groups. Critics said the tactic amounted to racial profiling and violated travelers' civil liberties.