WATCH: Moment when machine gun fire broke out at Las Vegas concert

LAS VEGAS: A horrific moment of a gunman appeared to open fire on gig crowds during a festival in Mandalay Bay, Las Vegas was recorded on camera. The incident left at least 20 people dead.

The rattle of a machine gun can be heard after the music cut at the Route 91 Harvest country music festival out and people hit the deck to take cover before starting to flee the area.

Police are currently looking for at least one active shooter, although witnesses say that there may be other people on the run. People are being urged to stay away from the Strip following the incident which happened while a country music concert was taking place.

Las Vegas is a major resort city, known primarily for its gambling, shopping and nightlife, which would have been packed at time the shooting broke out shortly after 10 p.m. ET.

And police said the toll may yet rise: “I don’t want to give you an accurate number because I don’t have it yet,” Lombardo said.

The shooting broke out on the last night of the three-day Route 91 Harvest festival, a sold-out event attended by thousands and featuring top acts such as Eric Church, Sam Hunt and Jason Aldean.

Police have disclosed no information that would suggest a motive for the shooting or revealed the identify of the suspect. The concert venue was in an outdoor area known as Las Vegas Village, across the Strip from the Mandalay Bay and the Luxor hotels.

The Mandalay Bay hotel is near McCarran International Airport, which said on Twitter it had temporarily halted flights after the shooting. Later, the airport said that some flights had resumed.