Prop gun sparks lockdown at Northern Valley Regional High School in Demarest

DEMAREST, N.J. (WABC) -- A prop gun sparked a brief lockdown at Northern Valley Regional High School in Demarest, New Jersey, police say.

A student came to school on Knickerbocker Road this morning carrying a prop rifle for the school's production of Hello Dolly, police said.

Some parents saw her and thought the gun was real, and they alerted authorities.

Police identified the girl within 10 minutes of responding to the scene.

They say she had permission to bring the prop gun to school.

Officials locked down the school for about 30 minutes during their investigation.