CHICAGO (CBS) — Three boys, ages 10 and 11, have been charged in an incident that sent a Chicago police sergeant to a hospital and damaged her car, police say.

The boys have been charged with misdemeanor criminal trespass to property after police say they threw rocks from an overpass, striking the on-duty sergeant.

The sergeant was in the 2500 block of West Cermak Road around 8:30 p.m. on Tuesday when her windshield was struck. She sustained a cut on her arm from the shattered windshield and was transferred to a local hospital in good condition. She was treated and released.

The three boys were taken to the 10th District police station for questioning. They were later released to family members after they were charged.

In a separate incident Wednesday morning, someone threw rocks and bricks from an overpass above Michigan Avenue in the West Pullman neighborhood, striking at least five cars.

No one is in custody in that case.