Chicago: A five-year-old boy playing with a rifle given to him as a gift accidentally shot dead his younger sister, officials said Wednesday, thrusting the issue of US gun violence back into the spotlight.

The boy’s two-year-old sister was pronounced dead after being rushed to a hospital following the shooting on Tuesday in rural Kentucky, police said.

Cumberland County Coroner Gary White identified the girl as Caroline Starks and said the children’s mother was cleaning the house at the time and had stepped outside onto the porch.

“She said no more than three minutes had went by and she actually heard the rifle go off. She ran back in and found the little girl,” White said.

The .22 caliber rifle had been given to the boy last year and was kept in the corner of a room. The parents didn’t realise a shell had been left in it.

“It’s a Crickett,” White told the Lexington Herald-Leader. “It’s a little rifle for a kid. The little boy’s used to shooting the little gun.”

An autopsy was set to be conducted but White said he expects the shooting will be ruled accidental.

“Just one of those crazy accidents,” White said.

It was the second fatal shooting involving minors in America this week.

The Anchorage Daily News reported that a five-year-old girl in a remote Alaska community had been shot and killed by her eight-year-old brother on Monday. The circumstances of the shooting were not immediately clear.

The United States has been embroiled in a heated debate over gun control and gun culture in the wake of a horrific December shooting at a school in Newtown, Connecticut that killed 26 young children and educators.

President Barack Obama has pushed for tougher federal gun laws to require universal background checks on gun buyers and called for a ban on assault weapons like the one used in Newtown.