Three more teen girls have been charged after an all-girl gang bashed a McDonald's worker and medical receptionist during a violent rampage in Cockburn on Monday afternoon.

The girls allegedly attacked people inside a medical centre. Credit:9 News Perth

The girls, aged between 12 and 15, allegedly assaulted eight people at several outlets at the Gateway Shopping Centre.

Police spokeswoman Susan Usher said eight girls were now facing charges over the violent spree, which left shoppers and shop owners traumatised.

On Saturday, police charged a girl, 13, from Hamilton Hill, a 15-year-old girl from Girrawheen and 14-year-old girl from Yangebup with assault and stealing among a string of other offences.