Police are investigating the shooting and trying to find out how the teen got the gun (Representational)

A 14-year-old American boy shot and killed five family members at their home in Alabama, before throwing away the pistol and calling police, officials said on Tuesday, in the latest high-profile gun crime.

The shooting occurred on Monday night in the town of Elkmont, a spokesman for the Limestone County Sheriff's Office told media, including an ABC affiliate.

The sheriff's office said five people were shot, with three dying at the scene and two later in hospital. "The 14-year old caller was interviewed and confessed to shooting all five members of his family in the residence," it said on Twitter.

"He is currently assisting investigators in locating the weapon, a 9mm handgun that he said he tossed nearby."

It was unclear where the teenager obtained the gun.

The killings follow a rash of mass shootings in the United States, including a weekend one in Texas that left seven people dead and 22 wounded, including a toddler.

Last month, a gunman killed 22 people and wounded another 24 in El Paso, Texas, while another assailant killed nine and injured 27 in Dayton, Ohio.

Amid renewed national debate, President Donald Trump said at the weekend background checks on gun purchasers would not have prevented recent violence.