A Georgia teen is facing charges including felony counts of making terroristic threats after he admitted phoning 911 to claim he placed a bomb in his high school, police said.

The 14-year-old Marrow High School freshman confessed Wednesday to calling in three bomb threats, two on Monday and one on Tuesday, that put the school on lockdown for more than two and a half hours each day. Police said he made the calls from a cell phone stolen from another student.

"We were able to get the subscriber information and track down the phone which had been passed around to multiple students at the school throughout the day," said investigator Josh Waites with the Clayton County Sheriff's Office.

Waites said three students stole the phone, and the teen, originally from Philadelphia and referred to as "Lil' Philly" by other students, made his third call Tuesday afternoon. According to the 45-second 911 call, the student claimed the bomb had been placed in the high school gym and requested $2 million before the bomb was set to explode at 3 p.m.

Police were able to track down the boy's aunt, his legal guardian, and arranged to meet with them Wednesday morning. After listening to the 911 calls together, the student confessed to making the threats.

The 14-year-old was charged with three felony counts of making terroristic threats, two counts of disrupting a public school, and three counts of filing a false report. He is being held at a juvenile detention center until his first court hearing on Friday. If convicted, Waites said, he could face possible confinement in a juvenile center until the age of 21, time in a military style alternative school, counseling, probation or be returned to his mother's custody in Philadelphia.

Marrow High School was placed on lockdown after each threat. Following both the Sheriff's Department's and the school board's policies, the school's 1,800 students were confined to their classrooms while police personnel and bomb dogs searched both the interior and exterior of the building, Waites said. Police found no evidence of any kind of explosives on the campus.

Waites estimated the cost of the lockdowns to be more than $12,000 to cover the overtime hours and additional personnel needed to search the high school.

"Lil' Philly" has been a student at Marrow High school since September 2011. The boy had no criminal record, Waites said, but had quickly collected a history of disciplinary issues at the school, including profanity directed at school personnel, throwing objects, failure to follow instructions and cutting class more than 50 times.

In October 2011, two students at Charles Drew High School, also in Clayton County and about 10 miles from Marrow High School, called in a bomb threat with a cell phone from a classroom within the school. Police were able to track down the students and apprehend them the same day.

"Most kids think threats are a prank," Waites said. "But in these times all threats are taken seriously, with things like Columbine or Virginia Tech and even the cost involved for the department. The students responsible will be caught. So think before you call."