A shooting on the main campus of the University of Nevada, Las Vegas, has claimed at least three victims before the bloodshed ended with the suspect dead.

In a message posted to X about two hours after responding to reports of a shooter at the school, police said: “Right now, we know there are three victims, but unknown extent of the injuries.”

Authorities have not identified the victims nor have they elaborated on their conditions. It also remained unclear whether the suspect was shot dead by police or took their own life.

Vincent Perez, a professor at the school, known by its initials UNLV, told MSNBC he had heard a lot of gunfire before taking cover on campus.

“I would say just seven, eight shots, one after another, loud and very loud,” he said.

“As soon as we heard that, we ran back inside and we realised this is a real shooting, and there’s an active shooter on campus.”

Official details of the incident remained sketchy.

After receiving a call reporting a shooter on campus, law enforcement officers “immediately responded and engaged the suspect,” university police spokesman Adam Garcia said at the briefing.

“The suspect is deceased,” he said.

Sheriff Kevin McMahill of Las Vegas Metropolitan Police Department said there was no longer any threat to the community, but the main UNLV campus and other branches of the university were being closed for the day “out of an abundance of caution.”

Officers were still searching through each building on the sprawling grounds to ensure “we don’t have additional victims or subjects,” the sheriff said.

Police said earlier on X that shots had been reported around Beam Hall, a campus building that houses the business school and other facilities. In a separate post, campus police said there was an additional report of shots fired in the Student Union.

The first reports of the incident surfaced around noon, and within about a half hour Las Vegas police reported: “The suspect has been located and is deceased.”

The UNLV campus has a student enrollment of some 25,000 undergraduates and 8,000 post-graduates and doctoral candidates.

The sheriff said students on the campus appeared to have been badly shaken, as were people in the aftermath of a mass shooting in 2017, when a gunman opened fire from a high-rise hotel window onto a music festival below along the Las Vegas Strip.

Sixty people were killed and hundreds more were wounded in what still ranks as the deadliest mass shooting by a single gunman in US history.

– AAP