A 15-year-old student opened fire with a handgun inside a rural Kentucky high school on Tuesday morning, killing two of his classmates, injuring 19 and sending hundreds fleeing for safety.

The shooter, who has not been identified, entered a common area at Marshall County High School in Benton shortly before 8 a.m. local time, 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.

Police were seen leading a teenager away in handcuffs and said the suspect will be charged with murder. It was the nation's first fatal school shooting of 2018.