A supposed publicity stunt for the action film Iron Man 3 did not pan out as expected, as moviegoers in Missouri called police over the weekend after seeing what they thought was a man carrying an assault weapon at a theatre.

The stunt, however, was a promotion by the management of the Goodrich Capital 8 theatre in Jefferson City. Actors dressed up to look like members of S.H.I.E.L.D., the superhero agency from Marvel Comics featured in the Iron Man and Avengers films.

The performance instead caused several moviegoers to call authorities, perhaps in light of the movie theater shooting at the in Aurora, Colo., last summer at the premiere of the Batman movie The Dark Knight Rises.

Armed police arrived at the scene after receiving frantic calls from locals.

"We received a series of 911 calls stating that a man dressed in all black with what appeared to be body armor with a rifle was walking into Capital 8 Theaters," said Captain Doug Shoemaker from the Jefferson City Police Department. "It's the opening night of a superhero movie, it's somebody walking in all-dark clothes... everything pointed to bad things about to happen. There's really no good that can come of this."

Manager of the theater chain, Bob Wilkins, apologized to cinemagoers for not warning them that there would be a performance following the film.

"We apologize and are sympathetic to those who felt they were in harm's way with our character promotion for Iron Man 3," he said in a statement. "This was not a publicity stunt. We have worked with the Cosplacon group on many movies to dress up and help entertain our customers. We have had many complaints about the members dressed specifically as S.H.I.E.L.D. operatives carrying fake guns.

"We didn't clearly tell our customers and some people didn't realize it was for entertainment purposes only. We apologize that police were called to come out to our theater...Going forward we will take the necessary steps to make sure this doesn't happen again. Security and safety for our customers is our number one priority."

Wilkins did not regret having the performance take place, however, saying his job is "to entertain people."

Tags: Iron Man 3