Children from Samuel K. Faust Elementary were outside for recess around 12:30 p.m. Friday when witnesses reported hearing what they believed were gunshots.
The children were brought inside as a precaution.
Bensalem Police say officers secured the school to ensure the safety of everyone inside.
Upon investigation, police say they learned the noises were from several young teenagers that threw two plastic soda bottle bombs. One landed in a school parking lot, but no one was hurt.
Four teens have been detained for investigation.
The lockdown was lifted shortly after the incident and the school went back to a normal schedule.
