A cyclist has died after being hit by a train on tracks close to the Southcourt crossing in Stoke Mandeville.
Ambulances and emergency vehicles are at the scene along the line on which Chiltern Railways operates.
A body was seen being removed from the scene.
An eyewitness told The Bucks Herald: “An adult was hit on the Mandeville road level crossing by a Chiltern Railways train to Aylesbury Town Centre after jumping the barrier.
“CPR was performed on the adult by paramedics at the scene.
“Five police cars attended the scene and set up a cordon.
“A helicopter and two ambulances attended the scene along with a private ambulance and network rail response team.”
The Bucks Herald can confirm a child and young adult were involved and that paramedics were seen performing CPR.
A local resident said: “It’s such a dangerous junction, a bell doesn’t ring and nothing warns you that a train is coming - too many people have died here now. “There’s a great irony that someone was here just last week getting signatures for a petition to build a bridge over the terminal.
“It’s unsafe and people shouldn’t be allowed to cross without warning.”
A British Transport Police spokesman said: “A cyclist has been seriously injured after being struck by a train at a level crossing in Aylesbury.
“Police were called at around 1.15pm following a report a woman with a bike had been struck on the Old Stoke Road crossing.
“Emergency services are at the scene and officers are currently working to establish the full circumstances of what happened.
“Anyone who witnessed the incident is asked to call BTP on 0800 405040 ref 209 of 09/11/16.”
Chiltern Railways were unable to comment.