Traffic is queuing in long tailbacks after a crash on the A47 close to Wisbech.
The collision occurred at Guyhirn, where the A47 meets the A141.
A Cambridgeshire Police spokesman said: "Due to an accident at the roundabout at the A141 and A47 at Guyhirn there is long tailbacks of four to five miles.
"Please try to avoid the area."
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