Three people were killed and another critically injured in a shooting at a Las Vegas university on Wednesday, police said, with the suspect also dead.

The incident at the University of Nevada, Las Vegas, a short distance from the gambling hub's tourist-packed Las Vegas Strip, was the latest in the United States, where gun violence is a part of the fabric of daily life.

"According to our investigators at the scene, we have three deceased victims and one additional victim in critical condition at a local hospital," the Las Vegas Metropolitan Police Department wrote on social media.

"The suspect in this #ActiveShooter incident is also deceased."

Police said they had responded to calls around midday and indicated that officers had engaged a suspect on the campus, where gunshots rang out in at least two locations.

Television footage showed police military-style vehicles moving near containment lines, as well as dozens of young people being escorted through them.

One woman told local broadcaster KVVU that she had heard a series of loud noises and fled into a building on the campus, from which she was later evacuated by police.

"I was just having breakfast and then I heard three, like, loud booms," she told the station.

"Then two more, and then police showed up there and ran inside... but then after two minutes boom, boom, boom, more shots. So I ran into a basement, and then we were in the basement for 20 minutes."

Three hours after the shooting erupted, the university continued to urge people to shelter in place, saying that police were working to clear each building in turn and that the investigation remained ongoing.

"Law enforcement will potentially be coming to your door, follow directions and exit calmly with your hands plainly seen," the university said.

Brett Forrest, a reporter from local outlet KSNV, told CNN he had been on the campus for an assignment and was continuing to shelter in place with dozens of students and faculty as they awaited the all-clear from police.

"We are told that they're coming building by building, slowly letting out each building making sure no additional victims or anyone else inside, so they might take a while," he said.

Universities in the area were shuttered for the rest of the day and flights into the nearby international airport were halted, the Federal Aviation Administration said.