Hundreds Evacuated In Sydney Opera House Gas Leak

About 500 people were evacuated from an area around the Sydney Opera House for several hours as authorities worked to fix a gas leak. 

Fire crews were called to the building in Sydney's CBD about 3pm on Tuesday after a small excavator hit a gas pipe during construction on the Opera House entrance.

Approximately 500 people were evacuated from the site's concourse area and adjoining restaurants as firefighters in protective gear monitored  gas levels.

Two crews managed a 100-metre exclusion zone around the site as gas company Jemena worked to cap the leak.

About three hours later, Fire and Rescue NSW and Jemena confirmed the gas pipe was capped and the exclusion zone lifted.

Earlier, photos from bystanders at the scene showed people being escorted away from the Opera House vicinity by police.

Roads around the area, at Sydney harbour, were closed for several hours as emergency services attended the scene.

As of about 7pm, northbound traffic was being allowed onto Macquarie Street as far as the roundabout at the Opera House.

Additional traffic controls are in place to manage access to the Opera House as all performances proceeded as normal on Tuesday evening.

With AAP.