At least 10 people were injured, three critically, today when a lorry and a train were in collision on an unmanned rail crossing.
The driver of the lorry, which was believed to contain slurry, was arrested after the accident at Little Cornard, Suffolk at around 5.35pm.
Network Rail said initial reports suggested three people were critically injured, including the train driver.
A spokesman said: "At around 1735 there was a serious incident involving a road vehicle, namely a sewage tanker, at a level crossing at Sewage Works Lane between Sudbury and Bures.
"The road vehicle was struck by the 1731 National Express East Anglia service from Sudbury to Marks Tey.
"Initial reports suggest that three people were critically injured, including the train driver. There is also walking wounded.
"The crossing is a user-worked crossing with gates and telephone. The Network Rail signaller did not receive a phone call from the user of the crossing.
"British Transport Police are on scene and co-ordinating the response."
Suffolk police said the driver of the lorry was arrested.
The train was believed to be carrying more than 20 passengers, and around 10 of these were initially described as walking wounded.
Others were not able to move, because of their injuries, and it was thought these were potentially spinal injuries, a spokeswoman said.
Ambulance, fire and British Transport Police officers were all attending, along with Suffolk police officers, she added.
Passengers were being evacuated from the train, which remained upright.
A fire brigade spokeswoman said that the rear of the train's two carriages derailed in the accident.
Sharon Smith, 49, who was in her front garden 200 yards away, said: "I heard a massive bang. Everybody in the area ran to see what happened. At first I thought it was a car accident.
"But when I ran up the road I could see two carriages had hit a tanker."
She said many passengers got out of the train and gathered at the sides of the road.
The fire brigade was on the scene within four minutes and she stood in the road to help clear the traffic, she added.
The ambulance service said it had dealt with 18 casualties, of whom 14 were "walking wounded".
Two people who had been trapped on the train suffered life-threatening injuries, and two others also had injuries which were less serious.
All were going to hospital for further checks - the majority to Colchester General Hospital, one or two to West Suffolk Hospital in Bury St Edmunds and one of the more seriously injured by air to Addenbrookes Hospital in Cambridge.