EXPLODED: Boxer Mike Tyson, 35, incited a melee at a New York news conference held Tuesday to announce that Tyson and undisputed champion Lennox Lewis, 36, will fight April 6 at the Las Vegas MGM Grand. Tyson reputedly took a swing at Lewis and one of his handlers, pointed to his crotch while yelling at Lewis and screamed profanities at some of the boxing writers. There were also unconfirmed reports that Tyson bit Lewis. The gathering was then canceled, and now the April 6 fight may never come off . . . NOMINATED: The Directors Guild of America named its five nominees for best director. Their winner usually goes on to win the Oscar. They are: Ron Howard ("A Beautiful Mind"), Peter Jackson ("The Lord of the Rings: The Fellowship of the Ring"), Baz Luhrmann ("Moulin Rouge"), Christopher Nolan ("Memento") and Ridley Scott ("Black Hawk Down"). The winner will be named March 9. The Oscars are March 24 . . . NOT NOMINATED: Golden Globe winner as best director Robert Altman, 76, was bypassed by his peers at the Directors Guild of America for his "Gosford Park." The American Film Institute, the New York Film Critics Circle and the National Society of Film Critics also named him last year's best director. As for the DGA snub, Altman told Variety columnist Army Archerd: "I didn't think about it. It would be another wrinkle in the road." As for the Oscars: "That would be nice, but those are things I don't think about" . . . EXPORTED: American Taliban member John Walker Lindh, 20, was taken from a U.S. warship to a military base in Kandahar Tuesday and placed on a plane with FBI guards for the trip back to the U.S. to face trial. The Associated Press reports that Walker was put on a long-range C-17 transport plane able to fly the entire distance non-stop to Virginia so he could not claim asylum in another country should the plane make a fuel stop . . . DIED: Stanley Marcus, 96, whose father, aunt and uncle founded the exclusive Neiman Marcus luxury goods department store in downtown Dallas in 1907, passed away on Tuesday. Marcus, who joined the family business after graduating from Harvard, had a lifelong motto: "I have the simplest taste. I am always satisfied with the best."