Traffic is heavy on the New England Highway at East Maitland after oil spilled on the roadway on Thursday morning.

Fire and Rescue NSW Inspector Paul Collis said oil had spilled along about two kilometres of the highway near Melbourne Street. He said it was believed to have come from a bus.

Emergency services were alerted to the incident at 10.20am and have been on scene since cleaning up the spill.

Transport Management Centre crews are also on scene helping to direct traffic. One lane has been closed eastbound, while westbound traffic was not affected.

Drivers are urged to avoid the area if possible and proceed with caution if travelling through the area.

There was also chaos further down on the New England Highway on Thursday when a truck caught fire at Beresfield.

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