The incident occurred at a cinema showing the Batman film “The Dark Knight Rises,”police said.
Police said that one suspect was in custody. However, it was unclear whether other suspects were involved.
A 24-year-old man was arrested in a car park nearby in possession of a rifle and handgun. He told police that explosives were stored at his home.
A bomb squad was on site at the Century 16 movie theater, police added.
The first showings sold out quickly for the much-anticipated summer blockbuster “The Dark Knight Rises.” The third and final batman installment may break opening weekend records.