Performances at Sydney Opera House are expected to go ahead this evening, despite a gas leak forcing the evacuation of hundreds of people at the location and its surrounds.

Just before 4pm today, emergency services were called to the iconic Sydney venue after an excavator hit a gas pipe.

More than 500 people were evacuated from the venue's concourse, surrounding restaurants as well as the nearby Royal Botanic Gardens as firefighters worked with Jemena Gas to determine the safety risk of gas levels in the atmosphere.

More than 500 people were evacuated. (9news)

Macquarie Street is closed southbound and the Wilson carpark at the location is not yet allowing cars in.

Traffic in the area is still heavy with drivers being diverted to Bridge Street and advised to allow extra travel time.