First pictures and video from Las Vegas mass shooting at Mandalay Bay Casino

At least 20 people have been shot dead and a more than 100 injured in a mass shooting at a concert on the Las Vegas Strip in Nevada.

It took place overnight on Sunday 1 October as hundreds of music fans gathered for the final night of a festival near to the Mandalay Bay Hotel.

Police have confirmed that "one suspect is down" but they have reiterated the need for people to stay away from the area while the active investigation continues, however, they do not believe that there are any more shooters.

But police warned that the gunman's companion, Marylou Danley, was still at large.

Joseph Lombardo, the sheriff of the Las Vegas Metropolitan police said in a short statement that the "primary aggressor is dead ... the scene is static."

The gunman apparently lived locally although his motives remain unknown.

The incident area surrounds the Mandalay Bay Hotel and Casino in the heart of the famous gambling and leisure district.

Images have emerged showing police officers taking cover as well as videos from social media of tourists and concert-goers running from the scene.

Roads were closed and flights were cancelled as police were called to the Strip to deal with the unfolding situation.

A spokeswoman from the nearby Las Vegas Hospital said that "several" people had been taken in with gunshot injuries with 14 in a "critical condition."

Las Vegas Metropolitan Police have urged people to avoid the area on what was a busy Sunday evening, with hundreds gathered for the final night of the Route 91 Harvest Country Music Festival.