Police in Surrey were called to reports of theft in Cumberland Drive in Esher at around 6.30pm yesterday before being called to Thistledene in Thames Ditton.
Three people were reported assaulted by a group of men while trying to steal a catalytic convertor.
One of the victims was taken to hospital with serious injuries to her arm and has since been discharged.
Police are urging anyone who may have witnessed the incident to contact police on 101