Boys allegedly hurled "giant screws" at a mum and her one-year-old child in Whitehall.
Police received reports of nails being thrown at cars in the Whitehall Road area at around 6.20pm on Wednesday (April 26).
Officers attended and searched the area, but the offenders had made off.
One mother posted in the BS5 Crimewatch Facebook group to say she was targeted by three boys.
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She wrote: "I was trapped in my car with my petrified one-year-old as they pelted giant screws towards us at full force.
"After running to my house I called the police, then went out to tell them I was taking photos and that the police were on their way.
"The lads legged it. It wasn't just us they were targeting. They ran away over the back gardens of Poets Close/Whitehall Road."
