Two teenagers died and more than a dozen were injured after a 15-year-old student opened fire with a handgun at a Kentucky high school.

Terrified pupils ran for their lives, ditching their bags and scrambling to get away from Marshall County High School in Benton, Kentucky – about 120 miles northwest of Nashville, as ambulances, police cars and officers with assault rifles rushed to the scene.

Students were said to have tried breaking down fences and gates in a panic to escape the building as the shooting began.

A 15-year-old girl died at the scene, while a 15-year-old boy was pronounced dead at a local hospital. The boy was one of six people flown to hospital in the wake of the gunfire. None of the teens involved in the shooting have been identified.

“I’m distraught from all of it. I couldn’t really focus driving home. I was shaking a lot driving back to my house. I’m still shaking,” 17-year-old Greg Rodgers, a student at the school, told NBC News.

Of the 17 injured, 12 were gunshot victims while five suffered injuries trying to escape. Governor Matt Bevin said at a news conference that one girl died at the scene.

Kentucky State Police Commissioner Richard Sanders said the shooter walked into the school armed with a handgun and started shooting. The governor said the youth was apprehended at the scene “in a non-violent way”. The suspect is expected to be charged with murder and attempted murder, according to police..

During the news conference at the county Board of Education, Governor Bevin paused to collect himself as his voice choked with emotion, when talking about the victims and calling on the assembled media to show restraint in their reporting.

“I beg of you again – respect the fact that these children belong to this community and to specific families in this community. And this is a wound that is going take a long time to heal. And for some in this community it will never fully heal,” he said.

There was no word on a possible motive for the shooting. ”There’s no good answer for it,” Mr Bevin said. “There’s 1,000 hypotheses we’re not going to go into.”

Governor Bevin advised the public to “not speculate or spread hearsay” regarding the incident. Agents from the the Federal Bureau of Investigation (FBI) and the US Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) have joined the investigation.

Mr Bevin later issued a statement via Twitter as well, in which he said it was “unbelievable that this would happen in a small, close-knit community like Marshall County” and cautioned the public to “allow the facts to come out”.

A local business owner Mitchell Garland said that students were “crying and screaming” while running out of the school in the immediate wake of the shooting.

“Everyone is just scared. Just terrified for their kids,” Mr Garland said. “We’re a small town and we know a lot of the kids.”

School shootings have taken place in California, Texas, Ohio, Illinois, Washington state and New Mexico already this year, although this is the first fatal school shooting of the year.

Marshall County High School is about 30 minutes from Heath High School in Paducah, Kentucky, where in 1997 a 14-year-old boy opened fire on students, killing three and wounding five.

“It’s horrifying that we can no longer call school shootings ‘unimaginable’ because the reality is they happen with alarming frequency,” said former Rep Gabrielle Giffords, who survived being shot in the head in 2011. She called on Congress to strengthen gun laws.