12.45pm: Delays continue on the South Coast Line despite train services resuming after an earlier grass fire between Unanderra and Dapto.
Services are travelling at reduced speed through affected area.
The 11.55am Kiama to Central service is now running up to 14 minutes late, according to Transport for NSW.
Commuters have been told to listen to announcements and check indicator boards.
A Fire and Rescue NSW spokeswoman said crews from Unanderra contained the fire about 12.25pm and are in the process of blacking out the area.
The spokeswoman said initial reports suggested there was a large fire in the rail corridor near Nolan Street.
The fire was fast-moving at one stage, she said.
RailCorp staff are assisting fire crews.
12.30pm: A grass fire burning in the rail corridor has brought South Coast Line train services to a standstill, with commuters told to expect delays.
Fire and Rescue NSW crews are on the scene of the fire, which is burning between Unanderra and Dapto.
Train services have been stopped while crews work to extinguish the fire, which is understood to have burnt about one hectare of grass.
The 11.55am Kiama to Central service has been held at Dapto.
More to come.