At least three people were killed, and at least two others were injured in a shooting at an In-N-Out restaurant in Twin Falls, in the northwestern US state of Idaho, on Saturday, local officials said.

The shooting began inside the restaurant before 2:30 p.m. local time (2030 GMT), CBS News reported, citing Joshua Palmer, public information coordinator for the city of Twin Falls. Details surrounding the incident remained unclear.

Twin Falls Police Chief Matthew Hicks said a suspected shooter has died. It was not clear whether the shooter was being counted among the three dead.

The identity of the suspect and a possible motive were part of the investigation, Hicks said, adding that hundreds of potential witnesses were expected to be interviewed.

"We believe the threat to the community is over," Hicks said at a news conference.

The In-N-Out location, the fourth in Idaho, opened July 24, NBC News reported, citing a news release from the California-based chain.

"We are heartbroken," In-N-Out Chief Operating Officer Denny Warnick said in a statement Saturday. "Our prayers go out to our customers, our associates, and all of their families. We are working with the Twin Falls Police Department to assist in the ongoing investigation."

(With input from agencies)