Dragged by her hair and battered with punches, a young worker is bitten on the arm and thrown to the ground.

She was set upon by a gang of teenage girls who she caught stealing from the Cockburn shop where she worked.

The shop owner, who did not want to be identified for fear of retribution, said the attack happened early last month but was just one in a spate of violence that had plagued Cockburn Gateway recently.

Camera Icon A group of teenage girls attack staff inside a Cockburn business. Credit: 7NEWS

He said the two female staff who were attacked in that incident, sisters aged 18 and 20, had since quit fearing they would be targeted again by the gang of teenage girls.

The incident was reported to police but no one has been charged.

The elder of the sisters said the gang of up to 20 teenagers at a time had tormented them for weeks leading up to the violent confrontation with verbal threats.

She said her younger sister was most badly hurt in the attack and suffered a black eye and other cuts and bruises to her face and arms.

“My sister was choked by the neck and pushed backwards by one of the girls,” she said.

“That’s when the whole thing broke out and they started punching. One of them pulled her by the hair and dragged her to the front.

Camera Icon The shop owner says his staff have been subjected to daily threats from the teenage gang. Credit: 7News

“I was trying to calm everything down and get these girls out of the shop. That’s when one of them punched me in the back of the head and then a few times to the face.”

The young worker said it took police more than an hour to arrive during which time the gang of teenagers remained outside the store hurling threats and abuse.

She said in the weeks since the attack the gang of teenagers had returned to the shop almost daily to threaten and intimidate the staff.

“They threaten us and they threatened me personally, one of the girls even spat at me,” she said.

“They would make constant threats to us like, ‘you should watch out, I’m your biggest nightmare, I’m coming after you’, and things like that.

“I don’t want to work in a place where I don’t feel safe. We were just trying to earn a little bit of money while we are at uni, we don’t want to go to work and get hit every day.”

Security at Cockburn Gateway Shopping Centre was bolstered in response to the latest violent attack on Monday, during which a gang of teenage girls attacked shoppers.

The incident on Monday started at a McDonald’s restaurant and continued to nearby medical centre where the rampaging girls allegedly assaulted several people including a receptionist.

Police also ramped up patrols in the area yesterday and deployed riot officers. Seven teenage girls were arrested over Monday’s incident but only two have been charged with minor offences.

Anyone with information about violent incidents at the shopping centre can call Crime Stoppers on 1800 333 000 or make a report online at www.crimestopperswa.com.au.