HOLTSVILLE, New York - A family film audience was stunned to get an unintended glimpse of a horror movie, which left some parents and their children shaken and the theatre chain apologizing for the movie mix-up.

The moviegoers were expecting to see "The Last Mimzy,'' the PG-rated tale of a brother and sister who discover a mysterious box of toys and become endowed with superhuman powers to help preserve humanity's future.

Instead, the crowd saw the opening scene of "The Hills Have Eyes 2,'' the R-rated sequel to a recent remake of a 1977 horror classic by the genre's renowned Wes Craven.

 "The Hills Have Eyes 2,'' which centres on National Guard troops who stumble on a clan of mutant cannibals, starts with a chained woman giving birth to a mutant.

"There were kids that were crying, there were people trying to cover the kids' eyes, they were caught off guard,'' said Anthony Rasco, who was in the audience when the scene was unexpectedly shown in one of the theatres at the Island 16 multiplex on Thursday. "By the time we could react and pull the kids together and figure out what was happening, we pulled them out of the theatre.''

Another patron said the episode had left his three-year-old son with lingering, and unsettling, questions.

"My wife is eight months pregnant, and he's been asking, `Is that what mommy's going to have?''' said Frank Doll, 31, of Mastic, N.Y..

Theatre staff soon stopped the movie, gave the patrons free ticket vouchers, and started "The Last Mimzy'' about a half-hour late, according to parents.

National Amusements Inc., which operates the Island 16 and about 1,500 other movie screens in the United States and elsewhere, expressed "deepest apologies'' in a statement Friday.

"We are working with our theatre's managers to correct this situation and ensure that it does not happen again,'' said the statement from the company, based in Dedham, Mass..