BETHLEHEM (AP) - A lockdown was lifted at an eastern Pennsylvania school after a phone threat about a gunman prompted police to search the building and grounds for several hours.

Bethlehem Area School District Superintendent Joseph Roy said police arrived at Liberty High School around 1 p.m. Wednesday.The school was dismissed around three hours later.Police said they searched from classroom to classroom and no guns or gunman were found. No injuries were reported.Authorities told WFMZ-TV that the 911 call came from an untraceable prepaid cellphone and stated someone was inside the school with a gum.Police said if the call turns out to be a hoax, an investigation will begin to find the caller.