A train has hit a vehicle on the line between Cambridge and Ely with paramedics treating a man in his 40s for a severe head injury, the East of England Ambulance Service has said.
A spokesman said an emergency call was received at 2.34pm on Friday with the East Anglian Air ambulance, a land ambulance, three ambulance officers, the hazardous area response team and police sent to the scene near Stretham in Cambridgeshire.
One patient, a man in his 40s, has been taken to Addenbrooke's Hospital in Cambridge for treatment.
A British Transport Police spokesman confirmed officers were on the railway line between Cambridge and Ely after reports a train had struck a vehicle on a level crossing.
Police were alerted just after 2.30pm.
The spokesman added that officers were being supported by the ambulance service.