The A1065 at Weasenham All Saints near Fakenham is currently closed both ways at the Rougham end following a car crash.
Police were called to the scene just before 1pm.
The collision was between a Skoda and a Peugeot.
One woman has been taken to Norfolk and Norwich University Hospital with head injuries.
An oil spill is also being cleared up.
A spokesman for Norfolk Police said the woman's injuries are not thought to be life-threatening or life-changing.
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