There are major delays across most train lines running through Central Station after an earlier power issue at the station on Thursday.
A spokeswoman for the Traffic Management Centre (TMC) said that, while the power supply problem has been resolved, it will take "some time" for services to return to normal.
At about 3.40pm, Sydney Trains issued further warnings on Twitter for more delays across the service due to “urgent power supply repairs”.
Commuters on the T1, T2, T3, T4, T6, T7 and T8 lines should expect some delays.
Changes have also been made to some T5 services.
Sydney Trains wrote that services were slowly getting back to normal on Thursday afternoon.
“Please continue to allow extra travel time, listen to announcements and check real time apps as stopping patterns may change at short notice,” Sydney Trains wrote.
Delays to some services due to urgent power supply repairs at Central earlier.— T8 Sydney Trains (@T8SydneyTrains) February 22, 2018
Please continue to allow extra travel time, listen to announcements and check real time apps as stopping patterns may change at short notice.
A TMC spokeswoman told Fairfax Media that delays ranged from five minutes up to half an hour on the affected lines.
Commuters are being urged to allow plenty of extra travel time.
A Sydney Trains spokesperson said customers should their trip ahead.
The power issue was first reported at 10.45am, according to the TMC.
The Sydney Trains spokesperson said the cause of the outage is being investigated.