Children as young as 12, eight and even five months old were shot dead in recent days in the United States -- deaths that highlight the dangers of easy access to weapons, and the difficulties of the gun control debate.

Negligence, and simple bad luck, are often to blame for these tragedies which, with each death, trigger a new round of soul-searching over the divisive issue of gun control -- but little action.

Last week, an 11-year-old boy fatally shot his 12-year-old brother in the head during a target shooting outing using live ammunition in Carrollton, Ohio, in what authorities have deemed an accident.

Criminal charges could follow, however, for the person who left the handgun left unsecured on a picnic table, the local sheriff told The Repository, the newspaper in nearby Canton.

And over the weekend in Tennessee, an 11-year-old boy was charged with first-degree murder after he allegedly fatally shot an eight-year-old girl, his neighbor, in the chest during an argument over a puppy, local media reported.

A 2000 study published in the American Journal of Public Health found that in more than 40 percent of households with both children and weapons, the firearms are not secured and not always kept under lock and key.

Fifteen years later, numerous awareness campaigns launched by both gun control lobbyists and pro-gun advocates have failed to curb the problem of accidental deaths.

"Child gun deaths in the US are so much higher than those in other developed countries because we have so many guns and permissive gun laws," said David Hemenway, a professor at Harvard University who specializes in injury prevention.

"Too many parents do not understand that their children's minds are not yet fully developed, and children cannot be expected to act like little adults."

- Don't say 'bang-bang' -

The powerful National Rifle Association, the main pro-gun lobby in the United States, quibbles with that statement, and even provides recommendations to parents on how to educate kids about guns.

"Guns are called guns in our house -- they are not bang-bangs, boom-booms, paw-paws," smiling "NRA mom" Julie Golob says in a video on the group's website.

Golob advises against buying toys that looks like weapons in order to avoid any potential confusion.

Today, a third of America's children live in a home with at least one weapon. Two million of them live near an unsecured weapon, according to the group Everytown for Gun Safety.

Other studies show that two-thirds of children know exactly where their parents store or hide their weapons, even if the adults are convinced otherwise.

But storage and security is only one part of the problem. Accidents take place everywhere, simply because weapons are everywhere.

The number of weapons held by civilians in the United States is almost the same as the size of the population -- roughly 320 million.

It is not unusual for young children in the United States to shoot using live ammunition, despite the risk of recoil when the gun is discharged -- and children's relative lack of awareness of how powerful that recoil can be.

In August 2014, a nine-year-old girl killed her shooting instructor with an Uzi submachine gun in Arizona when she apparently was unable to handle the recoil.

Four months later, a two-year-old boy accidentally shot his mother to death in an Idaho Wal-Mart by grabbing onto a gun she was carrying in a handbag specifically designed to conceal it.

- 'Out of control' -

These accidental shooting deaths have shocked people in the United States and sparked outrage abroad, where handguns are not as commonplace.

But neither accidental shootings nor mass killings like the campus rampage last week in Oregon seem to unblock the debate.

A year after the Arizona incident involving the Uzi at the firing range, children are still allowed to shoot at targets, according to The New York Times.

President Barack Obama angrily called on Congress to do more after the shooting at Umpqua Community College that left nine dead plus the shooter, and he plans to visit with relatives of the victims on Friday.

But despite the Democratic leader's fiery words, gun deaths continue unabated, and American cities are seeing a surge in homicides.

Children are not immune to the violence.

Since early September in Cleveland, children aged three and five have been shot dead.

And on Thursday, Aavielle Wakefield will be laid to rest after she was shot dead last week in her car seat, her all-too-short life ended at just five months.

"Like seriously man!!!! A baby shot in the chest in Cleveland. It's been out of control but it's really OOC. Ya'll need to chill the F out," NBA superstar LeBron James, who plays for the Cleveland Cavaliers, wrote on Twitter.