Police investigating the mass shooting of concert-goers at a music festival in Las Vegas have said they are not treating the incident as an act of terrorism.

But Nevada law suggests the Sunday night massacre of at least 50 people can be defined as such.

The state's statute says an “act of terrorism means any act that involves the use or attempted use of sabotage, coercion or violence which is intended to cause great bodily harm or death to the general population”.

However, police, who are early on in their investigation of the shooting that also left at least 200 injured, said it was too early to label the incident as terrorism.

Responding to questions about whether the killing was being treated as terror-related, Clark County Sheriff Joseph Lombardo said: “No not at this point, we believe it is a local individual, he resides here locally.

“We don’t know what his belief system was at this time.”

Nevada state law separately defines a terrorist as "a person who intentionally commits, causes, aids, furthers or conceals an act of terrorism or attempts to commit, cause, aid, further or conceal an act of terrorism".

Las Vegas shooting – in pictures Show all 15 1 /15 Las Vegas shooting – in pictures Las Vegas shooting – in pictures People scramble for shelter at the Route 91 Harvest country music festival after gun fire was heard Getty Las Vegas shooting – in pictures People carry a person at the Route 91 Harvest country music festival after shots were fired David Becker/Getty Las Vegas shooting – in pictures People run from the Route 91 Harvest country music festival after gun fire was heard David Becker/Getty Las Vegas shooting – in pictures A handout photo released via Twitter by Eiki Hrafnsson (@EirikurH) showing concertgoers running away from the scene (C) after shots range out at the Route 91 Harvest festival on Las Vegas Boulevard EPA/Eiki Hrafnsson Las Vegas shooting – in pictures People lie on the ground at the Route 91 Harvest country music festival after hearing gun fire Getty Las Vegas shooting – in pictures A man in a wheelchair is taken away from the Route 91 Harvest country music festival after hearing gun fire David Becker/Getty Las Vegas shooting – in pictures People stand on the street outside the Mandalay Bay hotel near the scene of the Route 91 Harvest festival on Las Vegas Boulevard EPA/Paul Buck Las Vegas shooting – in pictures FBI agents confer in front of the Tropicana hotel-casino after a mass shooting during a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Las Vegas police run by a banner on the fence at the Route 91 Harvest country music festival grounds after shots were fired David Becker/Getty Las Vegas shooting – in pictures An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival Ethan Miller/Getty Las Vegas shooting – in pictures Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip AP/John Locher Las Vegas shooting – in pictures A cowboy hat lays in the street after shots were fired near a country music festival in Las Vegas Getty Las Vegas shooting – in pictures Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Sheriff Joe Lombardo (2-R) speaking during a press briefing in the aftermath of the active shooter incident on Las Vegas Boulevard EPA

The incident unfolded late on Sunday when a gunman, named as 64-year-old Stephen Paddock, fired hundreds of rounds from the 32nd floor of the Mandalay Bay Casino.

The bullets rained down on an outdoor country music festival, with concert-goers reporting hearing what they described as automatic gun fire.