Four people are reported to have been shot dead and eight others wounded in a casino shooting in southern Nevada.
Police have not confirmed fatalities but are investigating whether the shooting involves members of a Hells Angels motorcycle group.
It took place in a Harrah's Casino in Laughlin, about 70 miles south of Las Vegas.
Larry Tunforss, a fire department spokesman in nearby Bullhead City says four had died and at least 50 people inside the casino were handcuffed.
CNN reports Las Vegas police have not confirmed or deny the reports of fatalities.
Harrah's Casino in Laughlin has confirmed the shooting. The casino was immediately closed after the incident happened.
Casino spokeswoman Laura Delacruz says Laughlin is celebrating the 20 year anniversary of the "River Run", which draws motorcycle enthusiasts, including the Hells Angels.
Around 100 people have been taken into custody and bridges over the Colorado River have been shut to traffic, American radio station KGMN-FM reports.