Police said the shooter was also killed in the incident.

"According to our investigators at the scene, we have three deceased victims and one additional victim in critical condition at a local hospital," Las Vegas police posted on X.

"The suspect in this #ActiveShooter incident is also deceased," the police said.

Following the incident, UNLV and all other southern Nevada System of Higher Education institutions across the state will remain shut.

University President Keith Whitfield described the incident as 'tragic'.

"Today is a tragic day for UNLV. We're all still in shock as we process the unfathomable event. Members of our community lost their lives and others were injured. My heart aches for our UNLV family," he said.

Adam Garcia, university police chief, was quoted as saying by BBC that the two campus officers engaged the suspect in a shootout before being struck and killed. 

UNLV student Mike Henderson told ABC News that he was in a hallway when the shooting started and immediately ran into a classroom and sheltered in place.

He said he was later escorted out by police and saw someone with their face down, bleeding.

"Not something I thought would ever happen to me personally," he said.

The suspect was a professor

The suspect in the shooting incident was a 67-year-old career college professor, media reports said.

The suspect has connections with schools in Georgia and North Carolina, but it is unknown what connection the suspect had with the school where Wednesday’s fatal shooting took place, reported CNN.

Police are not releasing the name of the suspect, who is also dead, until their next of kin is notified, Las Vegas Metropolitan Police Department Sheriff Kevin McMahill was quoted as saying by the American news channel in a news conference.

Reactions

US President Joe Biden condoled the incident and said in a statement: "Jill and I join citizens across our nation in praying for the families of our fallen, and for those who were injured during these latest acts of senseless violence."

"This year alone, our nation has experienced more than 600 mass shootings, and approximately 40,000 deaths due to gun violence. This is not normal, and we can never let it become normal," he said.

The President said: "For all the action we have taken since I’ve been President, the epidemic of gun violence we face demands that we do even more."

Las Vegas Mayor Carolyn Goodman posted on X: "Tragic and heartbreaking news coming out of @unlv. Praying for everyone on campus as law enforcement responds to the situation."