VOORHEES, N.J. (CBS) – Several students and a teacher were burned during a science experiment at a high school in Camden County, New Jersey.

Authorities say six students and one teacher were injured and required medical treatment when a classroom physics experiment sparked a fire at Eastern Regional High School on Laurel Oak Road.

The students had just gone through one of their routine fire drills at the school. Then 30 minutes later, they say they heard a second fire alarm. They thought they were practicing the same thing twice until they saw not only fire trucks, but also police and paramedics rushing into the parking lot.

“We were not allowed in for like an hour afterwards. They just started letting kids walk back in,” said Alex Neumann, a student.

“A fireball…I can’t say exactly how it happened because I didn’t attend the interview with the teacher,” said Louis Bordi, Voorhees Police Chief.

Students say the physics class was experimenting with rockets when one of them exploded.

“The flames hit the desk. It set papers on fire, and some kids got hurt, but it was just an accident,” said student Bill Nogenitz.

At least one student, a junior, suffered serious burns and was transported to Cooper University Hospital. The other victims were taken to Virtua Voorhees with less serious burns.

The incident is under investigation.

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