Brisbane's Port Office Hotel closed indefinitely after fire

It's survived three floods and now a fire.

Smoke began rising from the roof of the Brisbane's heritage-listed Port Office Hotel on Edward Street in the CBD shortly after midday.

Surrounding office buildings were forced to evacuate as fire crews fought the blaze.

It's believed the fire started on the grill in the kitchen. Although chefs put it out, the intense heat travelled up a vent, causing further damage.

"The heat from the exhaust ignited the plastic tubing or plastic piping around the air conditioning system," Queensland Fire and Emergency Services officer Samuel Carrigg said.

There have been no reported injuries.

The first pub to be opened on the site was the Shamrock Hotel in 1864.

The hotel was renamed in 1909 to become the Port Office Hotel, and has been refurbished several times. It was inundated in both the 1893 and 1974 Brisbane floods but was sandbagged for protection from flooding in 2011.

It was heritage listed in 1992.

The venue is closed indefinitely but the owners are determined to reopen.