SAN DIEGO - Twenty years after his Velociraptors and T.rex ruled Jurassic Park, director Steven Spielberg says the maneaters are returning to a movie theater near you -- teeth sharpened, and not for the popcorn.Spielberg on Thursday told audiences at the giant Comic-Con International convention in San Diego that he was at work on a new "Jurassic Park" movie, delighting a packed house at the pop culture showcase."We have a story. We have a writer working on the script, and I think we will see a 'Jurassic 4' in our foreseeable future, probably in the next two or three years.""Jurassic Park" thrilled audiences in 1993 with its modern-day dinosaurs developed from DNA in fossils that wreaked havoc upon a theme park where, instead of enjoying the wonders of science, the guests got eaten. The movie took in $915 million worldwide in its day and spawned two sequels.Spielberg made his first trek to Comic-Con this year to show audiences clips from his upcoming film, "The Adventures of Tintin," which was directed by the Oscar winner and produced by "Lord of the Rings" filmmaker Peter Jackson. It is scheduled for release in December of this year.The movie is based on the comic books by Belgian artist Georges Remi, whose pseudonym was Herge, and they tell of a young journalist and his faithful dog who find themselves on numerous adventures, solving mysteries.