The A1 is shut southbound at St Neots after a serious crash involving six vehicles.
Emergency services were called to the southbound carriageway, between Little Paxton and the A428, just before 7.40am.
Magpas Helimedix, three ambulances, a rapid response vehicle, and a paramedic officer attended the incident. An East of England Ambulance Service spokesman said three people were injured, two with back injuries and one with leg injuries.
He added that two of the injured were taken to Bedford General Hospital and the other was taken to Hinchingbrooke Hospital, in Huntingdon.
A spokesman for the Cambridgeshire police said: “This is a lot of disruption as there is a lot of traffic. There is a van involved where the occupants could have injuries, but it is not clear at present.”
The road was reopened shortly after 10am.
More to follow.
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