New Delhi, Aug. 3 -- A gunman opened fire at an In-N-Out eatery in Twin Falls, in the US state of Idaho, on Saturday, killing three people and injuring seven others before taking his own life, local officials confirmed, according to CBS News.

Twin Falls Police Chief Matthew Hicks said on Sunday that the shooter, identified as 24-year-old Chad Williams, died from a self-inflicted gunshot wound.

Hicks noted that investigators are attempting to establish the motive behind the attack, adding that the suspect's relatives are assisting law enforcement officers with the ongoing inquiry.

"Their hearts are also broken," Hicks said. Investigators said they are confident the suspect acted alone.

The incident occurred shortly before 2:30 pm local...