PEACHTREE CITY, Ga. -- Two teenagers are accused of injuring a postal worker with an explosive device put in a mailbox in an attempt to get back at a neighborhood bully, authorities said.

The teenagers, ages 15 and 16, admitted planting the device and have been charged with manufacturing an explosive device, Peachtree City police said.

Police said a potentially explosive device was thrown Friday onto the porch of a home to scare and retaliate against a 17-year-old who lives there.

A postal worker found a second device inside the home's mailbox Saturday and suffered minor chemical burns and an inhalation injury, police said.

The Clayton County police bomb squad detonated the device, and no other injuries were reported. Clayton police Capt. Greg Dickens described the device as a 2-liter soda bottle containing household chemicals designed to expand when mixed together.

The teens were getting back at a neighborhood bully, Fayette County Assistant District Attorney Greg Stein said.

"They were very foolish to do this, but felt they had no other choice because they were being bullied by this individual," Stein said.

The teens appeared Monday in juvenile court and were released to their parents.

The Fayette County Board of Education will hear the youths' case soon to determine whether they will remain in school, Stein said. The criminal case will likely be heard in Fayette County Juvenile Court by March, he said.

Peachtree City is south of Atlanta.