This photo taken by Liberty High School junior shows students sitting on a hallway floor as police search the building during a lockdown.
Liberty High School in Bethlehem, Pa. spent most of the afternoon under lockdown after a threat was called in to 911. But after officers spent hours searching, nothing was found.
Bethlehem Area School District Superintendent Joseph Roy said the lockdown was lifted around 4 p.m. on Wednesday.
It was after noon when someone called into the Northampton County 911 call center saying three men with guns entered the high school in downtown Bethlehem. Officials then placed the high school under lockdown out of an abundance of caution, school officials told NBC10.com.
A large number of officers responded to the school and began searching for any sign of weapons or suspicious items.
Liberty High School junior Oliver Taylor tweeted a photo of himself and classmates sitting on the floor in a hallway with a police officer keeping watch.
Taylor says there were reports of a gun in the school and that he and other students were patted down by police. He said officers also searched bags.
Police are continuing to investigate the incident which they are considering a hoax. Officials say the call was made using an untracable prepaid cell phone.
The high school will be open on a regular schedule on Thursday.