An armed high school teacher in Georgia barricaded himself alone inside his classroom on Wednesday and fired a gunshot when the principal tried to force open the door, but no one was seriously injured, police said after the instructor was arrested.
The incident unfolded as schools around the country remain on edge from a shooting rampage at Marjory Stoneman Douglas High School in Parkland, Florida, in which 17 students and educators were killed.
In response to that massacre, allegedly carried out by a former student, US President Donald Trump has said teachers should be allowed to carry concealed firearms on school campuses.
The incident at Dalton High School, about 90 miles (145 km) north of Atlanta, the Georgia capital, began when a group of students tried to enter a classroom and found that their teacher would not let them in, Bruce Frazier of the Dalton Police Department said.
When the principal arrived and tried opening the door with a key, a single gunshot was heard from inside the room, prompting a security lockdown and evacuation of the school as police were notified and the school's resource officer was summoned, Frazier said.
Responding to reports of gunfire at the school, officers from the Dalton Police Department found the teacher holed up inside the classroom with a handgun. He was taken into custody about 30 to 45 minutes later, Frazier told reporters.
The suspect was identified as Jesse Randal Davidson, 53, a social studies teacher at the school who police said also serves as the play-by-play announcer for the Dalton High School football team. Police initially spelled the teacher's middle name differently.
Davidson was charged with aggravated assault, carrying a weapon on school grounds, terroristic threats, reckless conduct, possession of a gun during commission of a crime and disrupting public school, the Dalton Police Department said on Twitter.
Only one minor injury was reported on Wednesday - a girl who hurt her ankle while fleeing in the pandemonium, Frazier said. The gunshot went out a classroom window but did not strike anyone.
Frazier said he had no immediate explanation of what may have precipitated the incident, and he declined to say whether he believed it stemmed from a suicide attempt.
"This teacher apparently did not want to involve students in this incident in any way," Frazier added.
Dalton High School Principal Steve Bartoo said at an afternoon press conference that Davidson was considered an excellent teacher who was well thought of and "fit to work" at the school.
"Our teachers care about our kids, they love our kids, they take care of our kids, and it's certainly shocking to me, probably shocking to any school principal if one of their staff members you know pulled a gun out in a classroom and fired," Bartoo told reporters.
Frazier said it was not immediately clear whether any students had previously been in a classroom with the teacher while he was armed.
Students at the high school, which has an enrollment of about 2,000 pupils, were taken to a nearby convention centre after the evacuation, authorities said.
They were excused from classes on Thursday but would be allowed on campus to retrieve personal belongings left behind in the evacuation, the school district said.
"It is really serious after so many things have happened all over the country," student Ricardo Perez told television station WTVC-TV in a telephone interview after the incident. "I'm shocked, I can't believe it. I thought it was a dream."