UPDATE 1.30pm:
Trains services are returning to normal after urgent track work delayed trains on the Eastern Suburbs and Illawarra line this morning.
There are still some delays.
Earlier story:
Passengers travelling on the Illawarra Line, South Coast Line and T4 Eastern Suburbs are advised to allow plenty of additional travel time due to urgent track equipment repairs at Oatley.
The disruption is causing major delays for commuters with some trains running up to 40 minutes late.
Train stopping patterns may change so passengers should also listen to station announcements and check indicator boards.
A shuttle service is operating between Cronulla and Sutherland.
People traveling from Cronulla to the city may need to change at Sutherland
ARNCLIFFE ACCIDENT
Drivers are being urged to avoid Forest Road at Arncliffe after a five car collision this morning.
Emergency services were called to the scene of the accident near Wolli Creek Road just before 8.30am.
The road was closed as emergency crews worked to remove cars from the road.
All citybound lanes have since reopened along with one westbound lane.
The accident has caused delays of up to 30 minutes to bus services in the area.