Drivers are being asked to find alternative routes after a crash between two cars on the A148.
Police were called to the A148 at Sculthorpe, near Fakenham, at 11.23am following a collision involving a Ford and a Vauxhall near to New Road.
Firefighters and paramedics were also called to the incident and the road is partially blocked.
Police remain at the scene and recovery has been called.
There have been reports of one casualty but they are not believed to be seriously injured.
In a tweet, Norfolk Police warned of delays and asked drivers to consider alternative routes.
For up-to-date information about the county's roads, visit our LIVE Norfolk traffic map.
Join our Norfolk Travel Information group on Facebook for all the latest traffic news in Norfolk.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here