FORT LAUDERDALE, Fla. (AP) — A gunman carried a shotgun in a guitar case and opened fire Friday in a Florida high school, wounding one student before he was arrested on a day planned for a national classroom walkout to protest gun violence, authorities said.

Nineteen-year-old suspect Sky Bouche said "Sorry," followed by "It doesn't matter anyway" to reporters as he was led from the school in handcuffs by several deputies.

It happened at Forest High School, which was put on lockdown. A 17-year-old boy was taken to a local hospital for treatment of a non-life threatening wound to his ankle.

Some students and teachers piled desks and filing cabinets against classroom doors as a makeshift barricade.

Police initially said Bouche was a student at the school, but later said he was a former student not currently enrolled. No charges were immediately announced. The sheriff's office posted video on Facebook of Bouche being led from the school.

"I didn't shoot anyone," he said to reporters. He ignored most of the other questions until asked what he'd say to the shooting victim. That's when he said, "Sorry."

The shooting comes just over two months after a gunman killed 17 people and wounded 17 others at Marjory Stoneman Douglas High School in Parkland, Florida. Nikolas Cruz, 19, faces the death penalty if convicted in that Valentine's Day shooting.

It also coincided with a nationwide student walkout to protest gun violence on the anniversary of the 1999 massacre at Colorado's Columbine High School. The Ocala school had planned its version of a walkout, students said.

Chris Oliver told the Ocala Star-Banner that his 16-year-old son, a Forest student, told him the shooting happened near his classroom. The boy told Oliver the shooter stood in a hallway and fired at a closed classroom door. The shooter then dropped the weapon, ran and tried to hide, the boy told his father.

Craig Ham, deputy superintendent of Ocala schools operations, said the gunman carried the shotgun in a guitar case into the school by blending in with students. Ham told reporters the shooter fired at the bottom of a locked classroom door, and pellets struck the victim in the ankle.

Jake Mailhiot's psychology class had just begun Friday morning when school officials announced a "code red" alert over the intercom.

"You could hear in their voice that this wasn't a drill," the 16-year-old junior said.

Prepared for such alerts, students and teachers leapt into action to barricade the classroom's one door and block the door's window.

"Our teachers started pushing file cabinets and desks toward the door, and a few friends and I joined in," Mailhiot said. "We also started tying together some jackets to hang out the window, in case we needed another way out."

In a photograph Mailhiot shared on social media, the classroom door is invisible behind a tall pile of furniture.

Mailhiot said about 15 people in the classroom waited over 30 minutes to be evacuated by Ocala police. They were instructed to leave with their hands up, he said.

The school had planned to participate around 11 a.m. in a walkout commemorating the Columbine shooting.

Marion County schools Superintendent Heidi Maier decided weeks ago that any students who walked out would be punished. Instead, Maier instructed the seven mainstream high school principals to meet with students to develop a topic of discussion for a 30-minute session. All such events were canceled Friday.

Marion County Sheriff Billy Woods praised the quick response by the school resource officer, as well as school personnel and first responders. In the Parkland shooting, school resource officer Scot Peterson retired amid accusations he didn't do enough to confront the Stoneman Douglas gunman.

The Forest resource officer, Marion County Sheriff's Deputy James Long, "did not hesitate. He went right in," Woods said at a news conference. Woods said Long heard a "large, loud banging sound" and immediately responded.

The sheriff said the Bouche wasn't injured, wasn't fired at and was arrested without resistance.

"Marion County does everything to protect their children," Woods said.

Afterward, all students were taken by bus with a police escort to First Baptist Church of Ocala, where parents gathered to pick them up, officials said.

Rachael Carter was at the church waiting to be reunited with her daughter, a 10th-grader who turned 16 this week. Carter's pastor called her when he saw a post on social media.

"I'm shaking like a leaf in a hurricane," Carter said.

She that once she's reunited with her daughter, she will "stick to her like Velcro."

Students who saw anything related to the shooting were being interviewed by investigators. Ocala police, the sheriff's office, the Florida Highway Patrol and the FBI were investigating. They divided into teams that cleared all buildings, vehicles and the parking lot area. Once all students were off campus, authorities began conducting a more methodical search.

Forest High has an enrollment of more than 2,000 students, according to the National Center for Education Statistics.

___

Associated Press reporter Jennifer Kay in Miami and Brendan Farrington in Tallahassee, Florida, contributed to this report.

Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.