The parents of a four-year-old boy who brought a loaded gun to his nursery school have been arrested. Police were called to Amite Elementary School in Amite City, Louisiana, after the child showed the pistol to his classmate.

US officers believe the child took hold of the registered weapon during the journey to school after it was left unattended in his mother's car, possibly mistaking it for a toy.

Amite Police Chief Jerry Trabona told Fox News: "I'm assuming she had it laying on the seat and he just reached down there, got it and put it in his book sack. She doesn't remember where the gun was."

The boy's parents, Kenji Steptow, 36, and 30-year-old Kenisha Steptow, have been charged with child desertion. Chief Trabona said the charge was the toughest the law would allow.

Describing the possible tragic consequences of the incident he added: "If the baby would have been thinking it's a play gun and shot somebody with it, you don't know where that bullet is going. It was a semi-automatic. If he would have pulled it, he could have pulled it again. There was another bullet ready to go."

Parents who have children at the school expressed their shock at the news. Michelle Brumfield said: "I freaked out because I'm trying to figure out, where's my child? Is she ok? What part was isolated? What happened?"

The child, who has not been named, has been released into the custody of a family member.