Las Vegas shooting: Kiwi witness says attack was 'terrorist mass shooting'

A Kiwi caught up in the Las Vegas shooting on Sunday night (local time) has called the attack a "terrorist mass shooting".

Ben Northrop told Newshub he was driving down the strip, when he heard people screaming and running.

At least 20 people have been killed and more than 100 others injured in the attack. Las Vegas police say one suspect is "down" and they currently believe they acted alone.

However, Mr Northrop and other witnesses report seeing multiple shooters, whom he said "shot off in other directions".

"We don't really know where to go... and they don't know who the shooters are. It's a pretty freaky situation," he said.

"There are three guys on the loose still apparently, so we should really get the f**k out of here."

Dozens of police raced to the scene, after initial reports of the shooting at the open-air country music concert.

Mr Northrop said the response was starkly different to walking down a street in New Zealand.

"There are a lot of snipers [and] a lot of machine guns," he said.

Police have since confirmed there was only one attacker.