Police say shots were fired from an SUV Thursday night and then between neighbors.
The incident happened on the 1500 block of 10th Street in Des Moines.
Police say a teenage brother and sister were waiting for a ride to a party from their cousin. The cousin was followed by a white SUV whose occupants fired several shots into the air.
The SUV drove off but the two teens and their family then got into an argument with a neighbor down the street.
Police say the neighbor reported seeing a gun, pulled out his own weapon and fired several shots towards the teen and their family.
The 15-year-old brother was hit in the leg and chest. The 18-year-old sister was hit in the arm and leg.
Both were treated for minor injuries and released.
Des Moines police have an eight officer summer enforcement team dedicated to patrolling the neighborhoods. That team isn't assembled until April.
A neighbor down the street says she hopes the officers currently on the streets will pay more attention to her block.
"It worries me quite a bit. It would be nice to have officers come by a little more often,” Charmaine Wade says.
So far, no charges have been filed in this case and no one has been arrested.
Police say the man who shot the teens had a permit to carry his weapon and likely acted in self-defense.
Investigators are also trying to figure out who was in the vehicle that the first shots were fired from.