Oli was spilled on the road after a crash between a van and a car on Tuesday morning.
It happened on the A1075 Dereham Road in Watton, shortly before 9am.
Police were called to the scene a few minutes later, where they remain as of 10am.
No-one is believed to have been injured in the crash, but some oil was spilled on the road.
It's causing some delays in the area, with sensors showing traffic build-up in both directions.
Konectbus said its Route 11 Dereham to Swaffham service, which runs via Watton, was suspended due to the crash.
Its 9.40am and 9.50am services were cancelled, with the potential for more disruption to come.
For up-to-date information about the county's roads, visit our LIVE Norfolk traffic map.
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