Multiple people were killed and several others injured in a shooting at an In-N-Out Burger restaurant in Twin Falls, Idaho, Police Chief Matthew Hicks said.
The shooting occurred on the afternoon of August 1, Hicks said.
Hicks said the gunman was also dead.
He said police believed there was no longer a threat to the public.
Authorities had not confirmed the exact numbers of people killed or injured.
Hicks described the scene as chaotic.
Witness Len Coen said he saw a person carrying an AR-style rifle emerge from the restaurant's drive-through area.
Coen said another person carrying a handgun then fired at that individual.
He also said a restaurant employee moved a woman with a chest gunshot wound to safety while they waited for medical personnel.
City spokesperson Josh Palmer said the initial investigation indicated there was one attacker.
Palmer said investigators were still working to establish the suspected attacker's identity and whether anyone else was involved.
Idaho Senator Mike Crapo thanked first responders for their rapid response.