An exclusion zone has been established in Campsie following a gas leak at a petrol station.
Fire and Rescue NSW are at the scene, with a 100m boundary set up.
The petrol station is on Canterbury Road.
Operations are still underway.
Transport Management have advised that Canterbury Road is closed in both directions, with the leak at Northcote Street.
Eastbound traffic is being diverted through Beamish Street, with westbound traffic down Park Street.
Motorists are advised to avoid the area or expect delays.
Bus routes 415, 444, 445 and others that pass through the area are diverting and missing stops.
Emergency services are at the scene and traffic crews are attending.