A three-year-old boy in the US got hold of a handgun from his mother's bag and fired a shot that injured both his parents.

The toddler apparently reached for an iPod but found the loaded weapon, according to police in Albuquerque.

The bullet first struck his father in the buttock and then hit the shoulder of his mother, who is eight months pregnant. His two-year-old sister was present but unhurt.

Local media reports say police believe the shooting was an accident.

The father was treated and released, while the mother is in hospital in a stable condition. They will be investigated for possible negligence charges.

The Albuquerque Journal reported the family was living in the hotel room where the shooting occurred.

Childcare officials are taking care of the youngsters.