A man has been arrested after 11 people were hurt in a series of "hit and run" car accidents.
There were "a number of casualties" in the Ely and Leckwith areas of Cardiff, said South Wales Police.
A 31-year-old man has been arrested and a van was seized.
The injured, adults and children, were taken to the city's University Hospital of Wales.
Their ages and conditions were not confirmed.
Early reports indicated there were around five different "hit and runs", and officers attended a number of locations including Crossways Road, Cowbridge Road West, Grand Avenue, and Sloper Road.
Police advised motorists to avoid the area.
Witnesses said they saw "at least seven ambulances" and scores of police vehicles in the Ely area.