According to WUSA and WRC, the shooting occurred Monday night at a 30th Street Southeast apartment. The two children, who are both 3 to 7 years old, were playing with the weapon when one child accidentally shot the other in her upper body, police told WRC.
The girl was rushed to a nearby hospital, where she is being treated for serious injuries, WRC reported.
No one has been charged in connection with the incident, but the investigation is ongoing, according to the news outlets. No further information was immediately available.