FIVE bandits used a machete and iron bars to smash into the Ashmore Pizza Hut where they grabbed $600.

The robbers broke glass panels at the rear of the store in Cotlew Street to storm into the store about 11.15pm on Sunday.

It was a terrifying ordeal for two staff members who had been about to lock up for the night.

The armed robbers forced the shift supervisor to the front of the store to get the takings from the front counter, which was under camera surveillance, while they held a 17-year-old female staff member hostage at the rear of the store.

Shift supervisor Duade Borg, 22, and Letitia Thomas, 17, were just moments away from putting the last of the night's takings into a safe when they heard a noise.

"I had just finished counting the till and was literally about 10 seconds away from dropping it down the safe when I heard a bang at the side door," said Mr Borg.

"I thought it was a bit suss but I thought it might have been the driver who had come back because he had forgotten something so I stuck my head out and I looked towards the street.

"I didn't see anyone, and then I looked towards the rear of the shop and there was one guy running at me waving a pole.

"They had all started screaming by this stage, just swearing, yelling and making noise and banging on the glass. One guy tried to follow me in through the side door but I slammed it shut and it locked behind me."

Mr Borg said the bandits then started kicking the side doors and tried to smash the glass, but failed and so turned their attention to the rear of the building.

"It was only a couple of seconds after that they smashed their way in through the back doors," he said.

Three men burst into the shop -- one armed with a machete and the other two with iron bars -- while two others stayed outside to keep watch.

"The first thing that came to my mind was, 'I hope they just want the money'," said Mr Borg.

"It was a bit sketchy because they just seemed that psyched up that they would just bash someone for the hell of it.

"The machete really did it for me. I sort of packed it in after that."

Mr Borg believes the gang had the business under surveillance before the robbery as none of the intruders went near the security camera at the front of the shop.

"And if they did get on camera it wouldn't have been much because I was made to get the envelope that held the last day's takings which was on the front counter," said Mr Borg.

"While this was going on Letitia was held at the back of the store. The guy with the machete grabbed the money and then left, which sort of put my mind at ease.

"But one guy that was out the front demanded that I take him to the safe and open it, but I couldn't because it was on a time delay combination, and he left straight after that."

Detective Acting Senior Sergeant Peter Gray said police were concerned because the attack had been well planned and had involved a high level of violence.

"We're taking this very seriously and we are very concerned about their actions," he said.

"There was certainly a level of violence involved and it's a very serious offence.

"They were using the iron bars and machete in a threatening manner and demanding the money and obviously threat ened the attendant. This is quite frightening for anyone."

Police said there was no security camera footage of the incident.

The offenders were described as males, all of average build and in their mid to late teens.

One wore a blue flannelette shirt and a dark balaclava, two wore 'hoodies' with blue and white bandannas around their heads and another had tape wrapped around his face.

Police urge anyone who may have seen a group of youths near the Ashmore Plaza to call Crime Stoppers on 1800 333 000.