A ferry passes the Sydney Opera House. File picture: David Gray/Reuters

Sydney - About 500 people were evacuated on Tuesday from the Sydney Opera House concourse and adjoining restaurants following a gas leak, firefighters said as they monitored the atmosphere for gas levels.

Fire and Rescue New South Wales said on Twitter gas company workers were fixing the problem. It did not provide any further information on the type of gas or the cause of the leak.

The Australian newspaper said the leak happened when a low pressure gas main was hit during construction at the venue.

No injuries were reported.

The World Heritage-listed Opera House with its sail-like roofs is one of the world's most distinctive buildings, and Australia's most famous landmark.