The deadly shooting marks the third mass shooting in Las Vegas so far in December.
A man allegedly shot himself dead after gunning down a woman and two children in a suspected murder-suicide in the northwest Las Vegas valley Monday morning, NBC News reported. A third child, who was also hurt was rushed to an area hospital where he "seemed to be clinging for life."
According to the Las Vegas Metropolitan Police Department, police were called to an apartment on Oso Blanca Road, near U.S. 95 and Durango Drive. The man who called 911 said he went to the apartment to check on his brother and found several people shot.
Arriving officers found five people with gunshot wounds, a man, an older woman, and three minors. The preliminary investigation indicates a man shot three children under the age of 14 and an adult woman before shooting himself.
All the victims were connected to the shooter, Las Vegas Police Lt. Robert Price said at an afternoon news conference. While he could not confirm the exact relationship between the man and the victims, he said there was "some sort of tie."
Mr Price did not immediately identify the man, who he said had been under house arrest in an unspecified court case, and added that further details on the shooting were still under investigation.
Calling it "a very sad and tragic event'', Mr Price also addressed people suffering from a mental illness or contemplating hurting themselves or other people to get help.
"It's the holiday season, people get depressed … there are people out there who are willing to help you. There's hotlines, there's friends, there's family, it does not have to end like this," police said on the scene.
The deadly shooting marks the third mass shooting in Las Vegas so far in December. On December 1, five people were shot, at least one of them fatally, in a "homeless encampment" in Las Vegas. The suspect remains at large.
Last week, three faculty members died and another person was hospitalised after a gunman opened fire in a building on the UNLV campus. The man who opened fire was a 67-year-old professor who was denied a job at the university, reports said. The professor, who has not been named yet, was later shot dead by the police.
Mass shootings are alarmingly common in the United States, where there are more guns than people. The United States has recorded more than 500 mass shootings this year, according to the Gun Violence Archive, a non-governmental organization that defines a mass shooting as four or more people wounded or killed.