Director Oliver Stone's film on the September 11 World Trade Center attack opened to tears and torment in the United States on Wednesday, reviving memories ahead of the fifth anniversary.

"World Trade Center" sparked debate about whether Americans are ready for a film focusing on the Twin Towers attack, where 2,749 people died, but moviegoers at an early New York screening commended it.

"It was touching, (Stone) did a good job," said makeup artist Rodney Ramos. "I feel like I'm closing something a little bit."

About 50 people attended a matinee screening at a Midtown Manhattan cinema. Many wept or were visibly shaken.

The movie, starring Nicolas Cage, is based on the true story of two policemen who raced into the World Trade Center to save people, but were trapped in the rubble of the collapsed buildings for 12 hours before their rescue.

"I can understand why people are not ready to see it yet, but I think that they will be surprised at how powerful and personal it is," said Leslie Friedman, a New Yorker who said she was not in the city on the day of the attacks.

Reviewers have said the often-provocative Stone had shown respect, restraint and patriotism in the film, but box office experts said the test would be whether people were willing to see it or considered the subject too sensitive.

"I thought it was nothing short of amazing. They did such justice to this tragedy it was unbelievable," said Carolina Troncoso from New Jersey.

Immediately after the disaster, filmmakers avoided the subject and even digitally erased or deleted images of the Twin Towers, including cutting a scene from "Spider-Man" in which the superhero plans to climb between the two buildings.

"I do not believe it's too soon to make a movie like this," said middle-aged moviegoer Bob Bloom. "It's five years. Are we supposed to wait forever? Pictures like this should be made."

But Patty Casazza, whose husband John died in the World Trade Center attack, said there would be people close to the disaster who would be unable to watch. She said if she did, it would be on home video.

"I was at a comedy show last night and the comedian was talking about Osama bin Laden ... and you think you can handle it but my legs just went to rubber underneath me," she told Reuters by telephone.

"So for me, yes, (the film is) absolutely too soon. And I don't know when it won't be too soon."

Some politicians, Lower Manhattan residents and emergency services who responded to September 11 seized on the new film to demand more government assistance for those who have become ill after breathing the toxic air at the collapse site.

"The heroes of the movie were freed from the rubble, but thousands of 9/11 heroes remain trapped by their illnesses and lack of help," Congresswoman Carolyn Maloney said in a statement.