A bomb squad detonated a small explosive device found in a student's backpack at a school in Vicksburg, Mississippi, on Wednesday afternoon.
A police spokeswoman said Thursday that the explosive found at Warren Central Junior High School would have caused little to no damage had it detonated on its own. She said it had the firepower of "two large firecrackers."
One student was charged with possessing knives and an explosive device on school property. Another student detained after Wednesday's scare was charged only with possession of a knife, according to a police press release.
Vicksburg police Chief Walter Armstrong said Wednesday that a student had alerted staff about a peer who'd shown him the item. The school was quickly evacuated, and nobody was injured.
"We are very grateful that the child came forward with information and prevented a serious incident that possibly could have taken place at school,” Armstrong said.
The Clinton Police Department bomb squad used a robot to remove the device. It was rendered safe at about 3:15 p.m.
Police searched the home of one of the two students who were charged, and found materials that could have been used to make the tiny explosive.
It's unclear whether the students will be charged as adults, and police haven't yet announced a motive in the case.
This story has been updated with new information about the device, the police investigation and the charges against the students.