FLAGSTAFF, Ariz. (AP) — An overnight confrontation between two groups of students escalated into gunfire Friday when a freshman at Northern Arizona University killed one person and wounded three others, authorities said.

University police chief Gregory T. Fowler identified the shooter as 18-year-old Steven Jones and said he used a handgun in the shootings at about 1:20 a.m. Friday. Police were still interviewing Jones and he had not been booked into jail Friday morning.

The university in a statement identified the student who died as Colin Brough. The victims being treated at Flagstaff Medical Center are Nicholas Prato, Kyle Zientek and Nicholas Piring.

"This is not going to be a normal day at NAU," said school President Rita Cheng. "Our hearts are heavy."

She called it an isolated and unprecedented incident and said classes would go on as scheduled Friday.

The parking lot where the shooting happened is just outside Mountain View Hall dormitory on the Flagstaff campus, which provides housing for many of the campus' sororities and fraternities.

Iowa City, Iowa-based Delta Chi Fraternity said Delta Chi members were involved, but Executive Director Justin Sherman said in the statement that the organization doesn't have detailed information about the identity of the victims.

Freshman Cameron Sands, 18, said he had pledged a fraternity and was supposed to move into Mountain View Hall on Friday.

"It's crazy. You don't think this stuff happens. When I think of Flagstaff, I think safety," he said.

Sands, who did not sign up for text alerts from the university, said he learned of the shooting in a phone call from his mother.

Student Maria Gonzalez told The Associated Press that she at first suspected firecrackers.

"I was studying for an exam so I looked out the window and see two people running, and that's when I realized they weren't fireworks they were actually gunshots," she said.

The gate to the dorm's main entrance was closed Friday, and police had the surrounding area taped off.

School spokeswoman Cindy Brown said the wounded were taken to Flagstaff Medical Center, which said it couldn't release any information on conditions.

Arizona political leaders voiced support for the university and surrounding community, with Gov. Doug Ducey calling the shooting heartbreaking. He said the state stands ready to help in the investigation and response.

Congresswoman Ann Kirkpatrick, who lives in Flagstaff, said her heart was hurting, but expressed confidence that the city "will only grow stronger in difficult moments like these."

The Flagstaff shooting comes on the same day that President Barack Obama is scheduled to visit Roseburg, Oregon, where eight students and a teacher were shot and killed last week at Umpqua Community College. The gunman in the Oregon shooting wounded nine others before turning the gun on himself.

NAU is a four-year public university that has more than 25,000 total undergraduate students at the campus in Flagstaff, a city about three hours north of Phoenix that is surrounded by mountains and ponderosa pines.

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AP writers Bob Seavey and Paul Davenport in Phoenix, Bob Lentz in Philadelphia and Matt Small in Washington contributed to this report.