A gunman wearing a pig mask has reportedly opened fire at a hotel in Las Vegas.
Guests and tourists have had to flee the city's famous Bellagio hotel on the strip.
Various American news sites have reported reported hotel guests dived under tables after the shooting began.
A picture of the shooter wearing a pig mask has surfaced on Twitter.
Reports suggest that the shooting is linked to an attempted armed robbery of a Rolex shop inside the hotel complex.