Mastbaum High School in Philadelphia is under lockdown after reports of a gun inside of the building. Police say they received reports around 1:30 p.m., which forced them to put the school into lockdown while they carried out investigations. Over a dozen police vehicles were seen outside of the school.
Mastbaum is located in the Kensington section of Philadelphia, in the lower Northeast section of the city.
The lockdown has now been lifted. There is no word as to whether police found anything inside of the school. (source) 5:18 p.m. ET November 20, 2017