Workers in the Highland Fair building in Bowral including Woolworths have been evacuated.
The evacuation warning went off around midday, with two Fire and Rescue NSW trucks responding.
Workers were able to return about 30 minutes later.
A Fire and Rescue Spokesperson believes the alarm was set off by dust on one of the detectors in the building.
The 2st and Power FM office were among those which were evacuated.
Police are appealing for information after two fires were deliberately lit in the Nowra area.
About 5pm on Tuesday 15 September 2020, NSW Rural Fire Service attended Depot Road, West Nowra, to extinguish three grass fires.
A second fire was extinguished behind the treatment works on Filter Road, West Nowra about 10.30am today, Wednesday 16 September 2020.
Officers from South Coast Police District commenced inquiries into the circumstances surrounding the fires.
Initial inquiries suggest the fires were deliberately lit.
Anyone with information, or who may have been in the area at the time of the fires, is urged to contact South Coast Police or Crime Stoppers on 1800 333 000.
Inquiries are continuing.
IMAGE CREDIT: NSW RFS Shoalhaven