One person was killed and three others wounded in a shooting at an Arizona university early on Friday before police captured the gunman, university officials said.
The deadly shooting at Northern Arizona University (NAU) comes just over a week after the October 1 shooting rampage at Umpqua Community College in Oregon, in which a 26-year-old gunman shot dead nine people, then committed suicide.
The first emergency calls came through to police at 1:20 am Friday, when most NAU students would have been in bed at the university campus in the city of Flagstaff.
The motive for the shooting -- just the latest at colleges and universities in the United States -- was not immediately clear and the identity of the shooter and the victims was not immediately known.
"I can confirm that there was a shooting on our campus this morning. There is one victim, three are being treated at our local medical center and the shooter is in custody," NAU spokeswoman Cindy Brown told CNN.
"The incident took place in a parking lot adjacent to our Mountain View resident's hall on the northeast side of campus."
The university will hold a press conference at 6:00 am (1300 GMT), said Brown, who described NAU as a "gun-free zone" and said there was a police department on the campus of 20,000 students.
NAU sent out alerts urging residents of Mountain View Hall dormitory to stay indoors.
"Like many people, I was asleep," said Brown.
"But of course this is a very upsetting thing for anyone to receive in the middle of the night. Honestly, our thoughts are with the families of the victims right now."
President Barack Obama was to meet with families of the Umpqua victims in Roseburg, Oregon on Friday.
In the wake of the Umpqua killings Obama angrily called on Congress to do more and warned that failure to act on gun control was a "political decision", vowing to keep pushing for reform.