A man is believed to have been hurt in an incident with agricultural machinery in Fincham.
Emergency services, including Magpas Helimedix and fire appliances from Downham and Lynn, were called to a farm in Fincham at 11am.
An East of England Ambulance Service spokesman said: “We were alerted to Fincham near Kings Lynn at 11am this morning.
“An ambulance, a duty officer, rapid response car, the Trusts hazardous area response team (HART) and Magpas Helimedix attended the scene. Our crews are also working closely with Norfolk Fire & Rescue Service and Norfolk Constabulary.”
Norfolk police has said it will be issuing a statement shortly.