A series of hit-and-run incidents in the Welsh city of Cardiff killed a woman Friday and injured 11 other pedestrians, including seven children.

Witnesses described a motorist deliberately driving into families walking home from school.

South Wales Police said a 32-year-old woman was killed, and other victims were taken to hospital for treatment.

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An unidentified 31-year-old man has been arrested and a van has been seized.

Authorities said that there had been at least five separate hit-and-run incidents across the city.

A woman who works in a store said a shopper in her mid 20s and two young girls, aged about 10, had bought some coffee before leaving her shop.

"All of a sudden I heard a bang. I looked out and across the road, one girl was on the floor and the other girl was screaming," Shady Taha, 29, told the BBC.

"I heard a [vehicle] speed off but I did not see it."

Ramesh Patel, who runs a store close to the site where the woman was killed, said customers had described how the van driver appeared to target pedestrians.

"Customers have said a white van purposely drove at people," Patel said.

The incidents took place as parents were collecting children from nearby schools and walking home.