Three people have been killed and another one injured after being shot at a US university.

The shooting at the University of Nevada, Las Vegas, a short distance from the gambling mecca's tourist-packed Strip, was the latest in the United States, where gun violence is a way of life.

"Three of the victims are confirmed deceased," Las Vegas Sheriff Kevin McMahill said at a press conference.

PHOTO | COURTESY people outside Las Vegas University

He stated that a fourth person was gravely injured in the incident but that his condition was later upgraded to stable.

In a statement, US President Joe Biden condemned the latest "horrific act of gun violence" to terrorize a college campus.

McMahill said at a press conference that police arrived "within minutes" to reports of an active shooter at 11:45 a.m. (1945 GMT).

According to campus police head Adam Garcia, two officers "immediately engaged the suspect in a shootout," and the suspect "was struck and is deceased at this time."

PHOTO | COURTESY people being evacuated

The event began during an outdoor gathering of students.

"Students were playing games and eating food, there were tables set up for them to build Legos," said McMahill.

"If it hadn't been for the heroic actions of one of those police officers who responded, there could have been countless additional lives taken."

Police have not released any other information on the victims' or gunman's identity and are in the process of notifying next-of-kin.

PHOTO | COURTESY students being evacuated

According to one woman, she heard a succession of loud bangs and retreated into a building on campus, where authorities eventually evacuated her.

Officers were still searching the campus, which will be closed until Friday.

Las Vegas is a gambling and entertainment mecca that draws millions of visitors yearly, many traveling to see high-profile events.