An officer confronted an armed 19-year-old man who opened fire at an Illinois high school Wednesday morning, an encounter that ended with the suspect injured and in custody. The officer was praised in the aftermath, as authorities said his actions saved lives.

The incident in Dixon, Illinois, unfolded when police received a report of an "armed male subject" in Dixon High School about 8 a.m. Wednesday, Dixon Police Chief Steven Howell said.

A preliminary investigation found that the suspect fired several shots near a gymnasium, Howell said. At that point, he was confronted by a school resource officer.

The suspect, a former Dixon High student, left the school when the officer confronted him, and ran, Howell said. The officer chased after him.

"While pursuing the suspect, the suspect shot several rounds toward the officer," Howell said. "At which time, the officer returned fire and struck the suspect."

The suspect was taken into custody, Howell said. His injury was not considered life-threatening. The names of the suspect and officer were not immediately released. The officer is part of the Dixon Police Department, an earlier post on the city's Facebook page indicated.

Dixon is a city in Northern Illinois, about 100 miles from Chicago, and was the boyhood home of Ronald Reagan. The press conference was streamed on Facebook by WQAD-TV.

No students, staff or other members of the community were injured during the episode, Howell said. Authorities did not believe there was a further threat, and think the suspect acted alone, though the investigation was ongoing.

Students and staff at the high school responded "extremely well" to the situation, Howell said, adding that the district has received police department training on how to respond to shooters.

"While removing students from the various classrooms, responding officers found the staff [and] students had barricaded the doors to the classrooms with desks, bookcases and other objects," Howell said.

Howell praised the school resource officer, saying he "could not be more proud" of him.

"With shots ringing out through the hallways of the school, he charged toward the suspect and confronted him head-on," he said. "Because of his heroic actions, countless lives were saved. We are forever indebted to him for his service and his bravery."

Lee County Sheriff John Simonton also lauded the officer's actions, saying he saved an "enormous amount of lives in the school today."

"In addition to that, we need to take a look at what happened at the school," he said. "Because we do teach the students and faculty how to respond to these types of events. And from what I've been told . . . they did exactly what we asked them to do during the training."

The incident on Wednesday was "horrific," Simonton said. Then he added: "However, it could have been a lot worse."