Police are appealing for information following a number of armed robberies at restaurants in south-western and western Sydney earlier this year.

The three robberies occurred between Thursday 6 February 2014 and Monday 24 February 2014, in the early hours of the morning on each occasion.

They also occurred at the same chain of restaurants, while a different outlet was targeted in each instance.

It’s believed the same offenders may also be responsible for another armed robbery at a Campbelltown business on Sunday 2 February 2014.

Officers attached to the State Crime Command’s Robbery and Serious Crime Squad have now formed Strike Force Nutba to investigate the incidents.

During each incident, at least two men entered the premises and threatened the cleaner with a firearm, while demanding they open the safe.

On Monday 24 February 2014, three men forced entry into one of the restaurants on the Hume Highway at Casula. The trio restrained the cleaner in the kitchen and fled the location a short time later with the safe. It was recovered later that day in a park at Ingleburn.

Following inquiries, investigators were able to retrieve data from the onboard computer attached to the safe, which has been sent to the manufacturer for further analysis.

While investigations into the Casula incident are continuing, police have now released a CCTV image of a woman who may be able to assist with their inquiries.

She’s depicted in the image wearing jeans, a dark coloured hooded jumper and white sneakers.

Police believe she may have witnessed the robbery and are urging anyone with information on her whereabouts to come forward.

Detectives are also interested in hearing from anyone with information on a blue and white motorcycle, which was seen at two different robberies.

The State Crime Command’s Robbery and Serious Crime Squad Commander Detective Superintendent Luke Moore, said police are very keen to hear from anyone with information on the robberies.

“No matter how insignificant it may seem, any bit of detail regarding these robberies may assist police in identifying those responsible,” Det Supt Moore said.

“In each case the offenders have forced entry into the premises, detained the cleaner at gun point and demanded access to the business’ safe.

“Our detectives are working hard to catch those involved, they will be held accountable for their actions and prosecuted to the full extent of the law,” Det Supt Moore said.