FORT WASHINGTON, Md. -- Two students were arrested after two bottle bombs were detonated as a prank at a Fort Washington high school on Wednesday.

Officials said two devices containing toilet bowl cleaner and tinfoil packed inside a plastic bottle were detonated inside Friendly High School at 10000 Allentown Road.

Two more bombs were found in the school, but they did not go off.

A bomb exploded in a bathroom at about 9:50 a.m. and a second bomb went off 10 minutes later in the hallway in front of the administrative offices, Prince George's County school officials said.

"I didn't know what it was," said senior Andre Briscoe. "I thought it was a gunshot."

One of the students involved was caught on surveillance cameras putting a device in place.

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Police arrested a senior and a sophomore. They questioned and released another senior.

Wednesday is the last day of school for seniors.

There were no injuries, officials said. The school was placed on lockdown. Students were taken to the football field while authorities search the school.

Many students used cell phones to call and text their parents to pick them up.

"He called me at work and stated that, 'Mom, can you please come and get me, it sounds like they're shooting,'" said Cynthia Briscoe, Andre's mother.

"I knew something was wrong because I didn't recognize my child's voice when he called me," Briscoe said.

"I'm sitting here at my desk. I'm working. This is the last thing you'd think would occur during your work day, so, yeah, it was quite frightening," said parent Chantice McBride.

Students were let back into school at 12:45 p.m. School officials said they believe the students set the bombs off while students were changing classes. School spokesman John White said the students probably learned how to make the bombs online.

The two students who were arrested could be charged with reckless endangerment and possession and manufacturing of explosives. The third student will face disciplinary action at school. The seniors will not be allowed to participate in graduation or senior prom.

A device similar to a bottle bomb was detonated at Crossland High School last week, officials said.

A 15-year-old brought a homemade bottle bomb to school, and it exploded in chemistry class, police said. No one was injured, and the teen was charged with the manufacture and possession of a destructive device and reckless endangerment.

Authorities have not said whether the incidents are connected.