SANTA FE, Texas -- Ten people were killed and several others injured in a shooting at Texas' Santa Fe High School Friday morning.
Gunfire erupted at Santa Fe High School, about 20 miles outside Galveston, not long after classes began around 7:30 a.m. CT, officials said. Authorities later found explosive devices -- including pipe bombs and pressure cookers -- in and near the school, the law enforcement official said.
According to CBS News, 17-year-old Dimitrios Pagourtzis has been arrested in the shooting. A second person -- also believed to be a student -- has been detained as well.
Two law enforcement officers are among the injured, according to the source who spoke anonymously.
This is the third school shooting in eight days across the United States, and the 22nd since the beginning of the year.
Witnesses described students running from the school as they heard gunshots; they also described hearing an alarm at the school, though the sequence of events wasn't immediately clear.
An armed person walked into an art class at the school and began firing what looked like a shotgun, a witness told KTRK.
At least 12 people from the school are being treated at three hospitals, authorities said. Seven people are at Clear Lake Regional Medical in Webster, Texas; two patients are being treated at Mainland Medical Center in Texas City and three patients are at John Sealy University of Texas Medical Branch in Galveston.
At least one police officer was injured.
The Santa Fe School District said that possible explosive devices were found on and off the school's campus. Law enforcement officers were on the scene "rendering them safe." The school has been evacuated.
Santa Fe School District Superintendent Dr. Leigh Wall has released a statement on the shooting:
“It is with great sadness that I stand here today to share with you that we experienced an unthinkable tragedy at our high school this morning. We are grieving the loss of members of our SFISD family. We have received an outpouring of support from across the state, and we appreciate your continued prayers for our students, staff and community."
Witnesses describe hearing an alarm and gunfire
Angelica Martinez, a 14-year-old student, told CNN she and her schoolmates were being evacuated at one point "like it's a fire drill."
"We were all standing (outside), but not even five minutes later, we started hearing gunshots," she said. "And then everybody starts running, but like the teachers are telling us to stay put, but we're all just running away."
"I didn't see anybody shooting, but like (the gunshots) were kind of spaced," Angelica said, adding she heard about four shots.
The witness who spoke to KTRK also said she heard an alarm. She didn't specify if that was before or after the gunfire she described in the art class.
She said she couldn't describe the shooter.
"I didn't look. I just ran," she said.
Another student, Dakota Shrader, told KPRC that she heard gunshots only after hearing an alarm in the school.
"I was in the history hallway, and as soon as we heard the alarms, everybody just started leaving following the same procedure as ... (a) practice fire drill," Shrader said, breaking into tears. "And next thing you know, we just hear ... three gunshots, loud explosions, and all the teachers are telling us to run."
The entire school district is on lockdown, district officials said.
The high school has about 1,400 students, according to GreatSchools.org.
Three shootings in eight days
Friday's shooting was the third at a US school in recent days.
On Wednesday, an Illinois school resource officer shot and wounded a former student who fired a weapon near a graduation rehearsal at Dixon High School, authorities said. The suspected gunman faces three charges of aggravated discharge of a firearm.
On May 11, a 14-year-old boy in In Palmdale, California, went to Highland High, his former school, and began shooting a semiautomatic rifle shortly before classes began. He was taken into custody and is accused of attempted murder. One person was wounded.