EAGAN (AP) - Eagan police say a 13-year-old boy was fatally shot by his 15-year-old brother while the two played "cops and robbers."

Police and paramedics responded to the home Sunday morning after the 15-year-old reported his brother was unresponsive and bleeding.

The 15-year-old told dispatchers his brother had fallen and stabbed himself while running with a knife. But when police arrived, the older boy told officers he had accidentally shot his brother.

While home alone with their 11-year-old sister, the boys found an unloaded 9 mm pistol their father stored in the house. Investigators say at some point the firearm was loaded, then thought to be unloaded while the boys chased each other.

Police say the 15-year-old unintentionally fired one round which struck his brother in the chest.

No one was arrested.