WORKERS in Grand Rapids, Minn., cut through ice to erect booms around a 100,000-gallon oil spill in the frozen-over Prairie River prized for its walleye fishing . . . VIETNAM HAS AGREED to return seven more sets of remains believed to be those of American servicemen missing in action since the Vietnam War, a U.S. Embassy spokesman said . . . LAWYER AND MAGAZINE EDITOR Gitobu Imanyara was charged Tuesday with sedition after he published an editorial indirectly accusing the Kenyan government of tribal favoritism.