Fire officials are treating the cause of the latest fire at the Corrimal Cokeworks as suspicious.
Fire and Rescue NSW were called to a medium-sized grass and bushfire at Railway Street, Corrimal just after 11am on Saturday.
Trains were shut down for a short period while firefighters undertook operations in the rail corridor.
Fire and Rescue NSW Illawarraduty commander, Inspector Jay Bland said while it was difficult to link this incident to a series of fires lit in quick succession in the Corrimal area earlier this week, the cause of Saturday's blaze was "suspicious".
Inspector Bland said Saturday's fire started in the grounds of the Corrimal Cokeworks, and occurred in two separate locations in close proximity, with one impacting on the rail corridor.
Firefighters were on-scene for about two hours, until the fire was completely extinguished just after 1pm.
Inspector Bland said it was fortunate the wind conditions were favourable.
"In other circumstances, it could have been worse," he said.
On Wednesday, a series of four fires lit in quick succession in the Corrimal area could have had "catastrophic" consequences, according to Fire and Rescue NSW.
Five fire trucks were called to deal with four separate fires lit in a 500-metre area around Railway Street, High Street and the rail line.
Meanwhile, atwo-storey residenceat Bombosustained extensive damagein a fire during the early hours of Saturday morning.
Just before 3am, firefighters were called to a house fire at Hutchinson Street.
Upon arrival, they identified that there was a fire on the second level of the two-level house.
The fire had also extended up to the roof-space.
Fire and Rescue NSW crews were assisted by the Rural Fire Service.
All occupants of the home escaped safely.
Firefighters had the blaze under control by about 3.20am.
A short time later it was identified that there was some asbestos there, and firefighters undertook some work to contain it.
Ambulance officials checked a couple of residents for possible smoke inhalation, and one person was transported to hospital.