BENTON, Ky. - A 15-year-old boy opened fire with a handgun just before classes started at his high school in rural western Kentucky on Tuesday, killing two fellow students and wounding a dozen other youths before he was arrested, the state's governor and police said.

The shooter, who has not been identified, entered a common area at Marshall County High School in Benton shortly before 8 am CST (1400 GMT), pulled out a pistol and began firing at students, witnesses told local media.

"I see this guy draw from his side and he pulls out a pistol. I didn't even know what was going on. And then it registered. About the time it registered, this guy was sitting here pulling the trigger into all of us," student Bryson Conkwright told TV station WKRN.

"I can hear the gunshots. He was shooting in our group," said Conkwright, showing where a bullet grazed his hand.

Authorities declined to discuss possible motives for the shooting. There was no immediate indication of how well the suspect knew the victims, but officials said he was believed to have acted alone and faces multiple charges of murder and attempted murder.

"There's no good answer for it," Governor Matt Bevin said at a news conference. "There's 1,000 hypotheses we're not going to go into."