She said there were at least four fire engines on the scene, as well as at least three police cars.
She said police had blocked off the roundabout on the corner of Gillespies Line, Tremaine Ave and Botanical Rd.
Police said they had closed nearby roads and asked motorists to avoid the area, seek alternate routes and expect delays.
Footage of the fire shared on social media shows people were inside the tavern when the fire broke out, escaping the burning building as smoke billows across the ceiling.
People in the area said they could smell and see smoke rising from the distance. Others were concerned about the risk to a petrol station next to the tavern.