A 13-year-old boy and two 16-year-old girls have been arrested for assaulting staff and members of the public at Costco, Majura Park.

About 5pm on Tuesday, the teenagers entered the store and allegedly assaulted several staff members, before attempting to leave.

The teens also allegedly assaulted several members of the public before fleeing the area on foot.

The trio were arrested in a nearby carpark a short time later.

The 13-year-old Gungahlin area boy has been charged with breach of bail and five counts of common assault, a 16-year-old Gungahlin area girl has been charged with unlawful possession of stolen property, two counts of possessing a knife, and two counts of common assault, and a 16-year-old girl from the Tuggeranong region has been charged with five counts of assault occasioning actual bodily harm.

Police say they have already spoken to a number of witnesses, but they believe there are other witnesses and members of the public – including those who were assaulted – who they have not yet spoken to.

Anyone with information should contact police on 1800 333000.