Officials in a Montana high school have dismissed students early to conduct a thorough search of the school after a magazine of ammunition was found in a hallway.
Authorities say a handgun was not found in an initial search of Sentinel High School in Missoula on Monday.
Missoula Police Sgt. Travis Welsh says a construction worker found the ammunition magazine Monday morning and turned it in to school officials.
They immediately imposed a lockdown, which prevents anyone from entering or leaving the school and keeps students in their classrooms.
School officials said in an email to parents that dismissing students after noon would allow for a more comprehensive search and would be the safest solution for the school.