A seven-mile stretch on the A11 is closed because of overrunning roadworks.
The section on the southbound carriageway between Snetterton and the A1075 Norwich Road in Thetford is inaccessible for motorists, according to a tweet by Highways England.
It added: "Apologies for the inconvenience, we will endeavour to get things back to normal as soon as possible."
The roadworks were believed to have started last night and it is not known when the road will reopen.
For updates visit the EDP live traffic map.
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